You might be able to make them work together but what says it's the appropriate mic you need ?
What kind of projects will you shoot ?

well what interests me the most will be the voice quality i get. I want to shoot short films, very small, as in 1-2 characters

that mic is in the budget i currently have

A shotgun mic is more directionnal than other type of mics and of course, it's mono. For one person talking and standing still, it might be a good choice but if you film a conversation and/or moving character, it may become a challenge.

If you have your mind made up on the camera, I'd buy it first, and then consider adding an external mic later if the internal mic does not perform well enough. It's a good value mic, but it still might be a waste of money better spent on other things, if the on-board mic works well.

Most amateur video sounds terrible because they either shot it in a room with terrible acoustics - or they shot it outside, where the slightest breeze makes the mic element(s) rumble. It will take more than a slightly better mic to overcome those obstacles. When I do something like you're describing, I connect a passive 2-channel audio interface to the camera - which gives me 2 XLR inputs and a ⅛" stereo output to the camera. I don't work outside unless the wind is dead-still. Often I can hide 1 or more mics near the person(s) speaking in set or scenery, I can boom a directional mic in close (but just out of frame), I can use a wireless Sennheiser ENG lavalier or handheld where appropriate, and/or a small 8-channel analog audio mixer with any combination of the above (in stereo or 2 discrete monos) into the 2-channel interface. I'll disable any Automatic Gain Control, and adjust the audio recording level manually. I take a pair of headphones to monitor levels, and wear them for the duration of the shot - because usually I also have to concentrate on operating the camera. The headphones are enough to alert me of any drastic level changes. In a perfect world that's a 3 or 4 man job, but in reality, budget usually dictates I'm making compromises on all of those tasks (boom operator, sound mixer, videographer) and doing a small project all by myself.

You have to think about what you're trying to portray. If it's an intimate conversation between two people sitting/standing a couple feet apart, it should NOT sound like it's recorded from across the room. The sound has to match the mood of the shot. If it's a promotional video of some kind, you would expect the presenter to sound like he's a few feet away - but not lost in the echoes / reflections of the room.

Please bear in mind that most of the big budget films, or television shows you see, employ dozens of experts, and then still do extensive overdubs in post-production in the comfort of a proper recording studio or soundstage. Great footage starts with great light, great audio is often 100% fake and layered in months after the footage is shot.

I hope it doesn't seem like I'm trying to discourage you, but you have to have reasonable expectations about the results you can get on a tight budget. Enjoy the experience, learn what works and doesn't work with the equipment you can afford, and keeping improving through practice and repetition.

Best of luck!

Hawk has a lot of great info above. In my mind, the most important part of what he wrote is about using an external mic to get your dialog. The worst place you can put a mic is on the camera. It is normally too far away from your actor to pick up good audio, but will pick up every little sound the camera or camera operator makes. To get good dialog, do what dvdhawk says. You need to get a mic within about 18 - 24 inches of the person's mouth to get good clear audio without a lot of room sound in it. You can use a lavaliere mic, though if you are going to hide it under clothing you run the risk of getting the rustling sound of clothing against the mic. The other normal way is to use either a shotgun (generally used for outdoors) or a hypercardioid (used in reflective surface environments indoors). The standards in the industry for shotguns (I'm only going to talk short shotguns here because they are the most common even though long shotguns are used on movie sets as well), would be the Sennheiser MKH-416 ($1100) or MKH-60 ($1500), the Sanken CS-3 ($1500), or on a little lower budget the Rode NTG-3 ($700). A good low budget short shotgun is the Audio-Technica AT-875R at about $175. For hypercardioids, the standard is the Schoeps CMC641, which costs about $1700. Lower cost options include the Audio-Technica AT4053 (about $500) and even lower, the Oktava MK-012 with hypercardioid cap (around $300 I think?). And then there's a good boom pole ($500-600), a Sound Devices field audio mixer ($2000 - 4000) , Sony MDR-7506 headphones ($100), maybe a couple of wireless lavaliere systems ($600 - 2000 each), cables, connectors, etc. And then of course a person to operate all this gear. Good audio isn't cheap.

Bottom line is that the Rode Videomic will allow you to get better general ambient sound than your current mic. But it will not get you better dialog unless you get it off the camera and close to your actors. You can't change physics.

Have fun!

Rob