I have a form in vfp where the users can create his own formulas like in excel
example excel formula Costo=iif(price=1,total*3,total*2)
the problem is that the formulas will be evaluated in a stored procedure and the user must write the next sql
/* Begin formula */
Cost = Case
when price=1
then total*3
else total * 2
/* End formula*/

this formula is stored in a field on a table for future evaluation

the big problem is HOW EVALUATE THIS FORMULA BEFORE SAVE IN THE TABLE
AND CHECK SINTAXIS LIKE QUERY ANALIZER DOES

does exists an Activ-x or dll for include in a form ?

Please help me!!!!!!!!!!!!!!!!!