Well, thanx to Deathbane I managed to do the only logical thing. Since the eq2ui mainhud file had the groupmember info on it, I decided to copy and paste the xml code from the window I wanted into YAFS mainhud xml file. I deleted the old groupmember window code inside the file and placed the code from the window I wanted and the UI seemed to work fine!!!
Now I have a neat small group window on my new custom UI :P