Link check to unique payment group

I am trying to write a BAQ report that lists the payments made by day. I can get all the check info but cant find a way to link them back to a unique payment group? The groupID field is not unique as it will allow the same group name to be used several times so I cant use that....

 Is there a way to link from checkhed.checknum to APChkGrp.Sysrow?

Brett