Norman,

You can use SET PRINTER TO NAME command to select appropriate printer.

SET PRINTER TO NAME < Name of the printer for invoice >
Report Form Invoice to printer
...

>Hi, I have the following problem
>
>I have an invoice format frx that uses custom printer and custom size, but sometimes the users wants to see a report, and all reports uses another printer that is letter, they change the default printer in order to see the report full size, but then the invoice frx is changed.
>
>How can I force that the invoice only works with this printer and format and not affect the other reports and viceversa
>
>thanks
>
>norman