sure you can. But there will be a delay of a few millisecends if you're porting-out to a 3-head machine.
So, you'll need to fix the offset later, when you're mixing in these new tracks.
You can also print-to an analog tape on a cheaper, two-head machine, but then you'll have to play back the tape into your computer after the fact, in real time. But beware, there will be drift that way, 'cause analog machines don't run with the same precision and sync-lock that digital does. They can get close with a syncronizer, but if it's just a 2-head machine, chances are they won't have that feature anyway.
Best to "print-through" a 3-head machine, playing it in real time.
For more info on this and a whole lot more, check out this month's Electronic Musician magazine (March 2007) and read the article endtitled: "Joining the Reel World".