Add a new data field in self service form

Hi Team,

I have a question about how to add a new data field in self service form.

example:

In R12 - Payment batch process is introducted via self service forms.

Fields like Supplier site, remit to supplier site which we could see from Payments form and these fields are not available in Select Scheduled Payments window (Part of Payment Process Request).

Can any one suggest is there a way to add these fields as part of the displayed values in the self service web page.

Any suggestions are welcome.

Regards,

Srini