yes.
I assumed you had valid entries in each row.
you can try to add anopther condition that will exclude your '' or null values
isdate(mid({table.strindate},5,2)+'/'+right({table.strindate},2)+'/'+left({table.strindate},2)
and
date(mid({table.strindate},5,2)+'/'+right({table.strindate},2)+'/'+left({table.strindate},2)) in {?StartDate} to {?Enddate}