The first way I would attempt to do something like this would be to import the drum audio track, then open the Cubase sample editor, and enable Musical Mode under AudioWarp with the Elastique Pro algorithm.
Assuming your audio event is well edited (starts on the first beat, stops at end of last bar) and Cubase knows the source material’s correct tempo (its tempo analysis isn’t always accurate), you basically don’t have to do anything; Cubase will automatically arrange the beats to sync up with your project.
If Cubase can’t figure out the proper tempo or exact beat/bar length, you can specify that stuff in the sample editor. I use Native Instruments Traktor to do BPM analysis on audio files. It seems to get things right the first time a lot more often than Cubase does.