In Platinum, How can I transfer an event (guitar track-audio) from one song into another song? Also, the tempos are different.
thanks.

Basically, open the source project, drag 'n' drop the relevant guitar clip to, say, the desktop, and close the project.
 
Now open the target project and drag 'n' drop the clip to where you want it.
 
To fix the tempo, ensure the start of the clip is where it should start in your song, then go to the end of the clip, hover the mouse over the end of the clip (edge goes blue), press Ctrl (edge goes yellow), now press the left mouse button and either shrink or stretch the end to fit.

Hi. ^^This, or you could open both projects, and drag over from old to new project.
All the best.

worked...thanks guys!