What kind of help do you need? A common step missed when recording midi is rerecording it as an audio file before you export your song. Tell us more about your problem and it makes it easier to answer. Whaazup!
I'm having the same problem, so I'm interested to know if anyone has any advice as well.
I'm using a vst instrument in cubase SX, and would like to export that into a wav file. The manual says that I need to re-record it as an audio track, but how do I do that using midi?