Do you know the file name that will be used for the XML when it is submitted to the form library? If you do - you could add a field in your form that has a calculated default that includes whatever the file name will be along with the rest of the URL - then submit that to a list column. I think the format to submit to a hyperlink column is:
http://whateverTheUrl, display text
So - url then comma and space then display text - you may need to experiment a bit with that.