SQL - Using Case in Where clause

["Lim Hock-Chai" <Lim.Hock-Chai@xxxxxxxx>]

If FILEA contains FIELD1 and FIELD2 and I want to give user an option to 
selection records by FIELD1 that is >, >=, =, <, or <= the value he/she entered 
on the screen, what would be the best way to do this using Case in where 
clause?  Let say host variable field1Filter contains the option that user 
selected.
 
I wish I can do below, but it is not a valid SQL statement.
 
Select * from FILEA
    where case field1Filter 
        when '>' then
             FIELD1 > :screenField1
        when '>=' then
            FIELD1 >= :screenField1
         .....
        endcase
 
Any suggestion?
 
 
Note: Do not wish to use dynamic prepare sql statement.
 
thanks