SONAR 5 does have groove clips.
You'll want to choose a loop that's already close to the project's tempo, and then stretch or compress it to match the project. Or do it the lazy way and start your composition with the loop and build the song around whatever tempo it's at. That why loops typically come already at common tempos such as 60, 120 and 140 BPM, and often have the tempo in the file name. The SONAR 5 help file has enough information to get you started. Look up "Groove Clips".
Basically, think of the loop as a piece of the drum track that's going to be repeated as many times as you need. It's just an audio file. Once you've converted it to a groove clip, it's still an audio file but now it has additional information embedded in it that allows the clip to be stretched to adjust tempo or to change pitch.
The cool thing about groove clips is that they can be made any length you want, regardless of what length they start out at. You can start by dragging in a 2-measure fragment and then simply drag it out to five minutes if you like. This is how I normally create click tracks (although I'm using MIDI groove clips instead of audio - same principle).