You are right on the "exprnum=3", should be 2 since I have 3 layers. As for the search=Owner, its an attribute in the CULPR field. Maybe this will help you see what I got going on. Still nothing when I change it to "exprnum=2" though.
<expressions>
<expression alias="Status" textsearchlabel="Search Status (Owner/Renter) [ Example: Owner ]:">upper(CULPR) = upper('[value]')</expression>
<expression alias="Improvements" textsearchlabel="Search by Improvements [ Example: Y or N ]:">upper(Improvement) = upper('[value]')</expression>
<expression alias="Price" textsearchlabel="Search Price Range By Code [ Example: A($0-10,000), B($10,000-20,000), C($20,000-50,000), or D($50,000+)]:">upper(classcode) = upper('[value]')</expression>
</expressions>