I don't know of any other replacement keystroke combination for <ctrl><break>. I guess the appropriate question here is, how can you have a computer keyboard that doesn't have a break key, unless you've damaged it or built it yourself?
Assuming there is no answer to that, here are some things you can try:
Before you start execution, just set Breakpoints at likely places in your code. If you have a lot of code, this could be time consuming. Then you execute with the Run button, look at your breakpoint, then either hit F5 to continue until you get to the problem code, or F8 to step through line-by-line.
If you don't want to do that, you can just kill execution with TaskManager. The drawback with this approach is it completely kills VB so you lose any unsaved changes, and won't stop at the executing line.