What we've done for this is used the Descriptive Text field as Terry suggested, of course you have to house the file somewhere in order to have a link to it. So we either house it within the Request Queue, since that is a project you can just upload it to the documents tab. Or if that custom form will be used on Queue Topics in various Request Queues, we house the file in the documents of another project specifically for housing those kinds of files. Then the requester can download the file, fill in any information and upload it back into the documents section of the request. We also generally have a question toward the end of the form that says "Did you remember to upload your file to the documents area" and we make that a required field.