Hi Sandy_Wood,
Well, you could promote the form's unique name and add a receive data connection to the original SharePoint library that queries by first setting the form's name and then querying. That will give you the ID of the form in the original library but maybe that's not going to help.
qRules has a DeleteFromSharePoint command that will remove the item. A SharePoint workflow should also suffice. You just have to have the link. If you save your form's name in the form then you can just prepend the original form library using concat("http://site/original_library/", <formname>) and promote that field. Then, the workflow can use it to delete the item. Or, so I think ....
Best of wuck