UPDATE:
could make it with:
Datasource: texzibe
Template: BUSCAR.HTX
SQLStatement:
+select *,einicial+entradas-salidas as exis
+ from prod where
+nombre like '%M_nombre%%%' .and.
+color like '%M_color%%%'

but know the problem is how to put that in upper() so it matches in lower or upper case entries

Thanks, really urgent