1. Unprotect your template.
2. Copy the macro from the Add-In to your template then modify the QAT to put a button for the macro on the QAT.
3. Installing Macros
4. Modifying the QAT and Ribbon in Microsoft Word
5. Save the modification in the template, not for all documents.
6. I would recommend also assigning the F7 key to the macro, again saving the shortcut in the template.
7. I forget how I got the Check icon. Either by clicking on the modify button in the QAT modification dialog, or by editing the XML in the template.
8. The method for modifying the XML requires that you follow the directions on Greg Maxey's page. Modify Quick Access Toolbar (QAT) Button Image or Text

I'll check later and see which image I used if I modified the XML. Actually, when I think of it, I suspect you could simply copy the XML for the customization directly from the template.