You didn't say what version of Cakewalk you're using. I use CWPA 9.03, and here's how I do it:
1. Split your tracks at the place you want to insert events;
2. Highlight the stuff on the right side of the split;
3. Edit->Slide, specify 4 measures;
4. Hit Okay.
5. Copy and paste your 4 measures into the vacated time.