See SET FILTER and SET KEY commands in Help.

The better way could be in using PView, because filters are usually slow, especially in a form with grids...

>Hi,
>
>I have a form using private data session, in the form's data environment there is one table, which I want to programatically define the filter when the form starts up.
>
>How? ;)
>
>TIA
>
>Alonso