> This is just a simplified example. There are multiple input
> parameters and the where clause will get more complex. Do I have to
> live with having the stored procedure check every record in my example?

First,
check if what you want to do can be done by other means, supposedly by
changing the logic in the application. As long as you only give a
simplified example, where A matches A, B matches B, C matches C....
only you can decide if this is possible.

Then, if no change in the logic behind is possible, check out "execute
statement". Only recently I heard from the experts that one should not
make too wide use of it.
I have in fact only 2 or 3 places where I am using it, where I was
mapping old data structures from another database into my Firebird
databases.

I have too little time to rewrite the structure and "execute
statement" is working fine for me. "execute statement" was already
available in 1.5.x

André