Hide invoice attachment from user for some specific suppliers

Hi,

In the invoice creation form we can attach a document. We want that the attachment will not be viewable based on a conditaion like if the supplier is A, B, C from a responsibility say AP Inquiry. Some of the invoices may have attachments which are sensitive and should not be viewable by all. We want to restrict viewing some attachments based on a condition say specific supplier form specific responsibility. Other non sensitive attachment should be viewable with same responsibility. We want the restriction to be applied suppier name and responsibility wise.

Please help.

Regards,

Syed