Word Mail Merge VBA Application Start Up Form

I have a user form created in Word 2010. It is built in behind a word document that does a mail merge. In other words the code in the form does the work of doing the merging. ie: choosing a source file and importing its data into the merge document. The code saves and closes it too. So how do I get the form to come up right away when the user opens the file?
I don't want the user to have to open the document, F11 to get the source code, double click the form and click the run button.
Right now I have a "normal" project in the explorer and I have my project that holds the form. I guess the "normal" project is there because it is attached to the actual word document. I make no changes to the document. It is just a template to use. I hope what I describe is understood. I can elaborate.