Umm..since I dont get into programming Im not sure how well I could help you in this department! The best I could do is to see if you need permission to use that type of code..DirectX is Microsoft and you need to get the developers kit from them I believe..VST I think is Steinberg's protocol but I'm nto too sure on that one to be honest. I know that there was a dicussion about making some plugins on the DAWworld computing section awhile back..but nothing about getting rights or any legal mumbo jumbo. I'm sure someone will be able to jump in here and help out...Anyone? Beuler?
Opus

Arf. With a VST-DX adapter like FXpansion´s VST-DX adapter, you can use most VST plugins as DX plugins. In SONAR, you can even use VST instruments as DX Instruments. SONAR can use VST plugins and Instruments just as well as DX counterparts.

sounds like someones late

The VST adapter is great but you CANT use the UA dsp card with it

UA has gioven one to angus at fxspanison ( so the story goes), but he hasnt gotten it working yet as far as I know :(