IMHO, you won't get much out of your question. Most likely a performance problem is not cause by one single line of code. Plus you won't get such information out of promon.
Generic performance problems can rear their ugly head because of many possible reasons. Since you don't elaborate on what exactly your performance problem is and there is no generic advice it's subject to pure speculation as to what could be the reason for your struggles ...
Is there a specific reason why you don't talk about your Progress/OpenEdge version and the OS you're running on?
Heavy Regards, RealHeavyDude.