Record sample MC4000

Hi guys, I introduce myself. My name is Marco and I come from Italy. This is my first time in this forum and I hope that you could help me. I recently bought MC 4000 and is a very good product… I would like to record a sort of loop and put in the sample, because I need to run it as a sample… I really can’t find anything on the web, if I try to record sample from the sample pad it takes all the track into the sample pad…I need (example) just 4/4 bass from the beginning to get in loop… Could someone help me? thank you so much guys…I hope that I explained well…