Print smarform to a non-default printer?

I am writing a print program to manually print a smartform.

Which means, no SAP output message is involved. No entry created in the table NAST.

I assigned the printer short name to the output_options-tddest. It only prints if the printer is same as the user default printer in the user profile.

Any one has experience on how to print a smartform to a non-default printer?

Thanks a lot.

Margaret Chen