How to add button/toolbar to one workbook only when it opens

Could someone help me by suggesting a code that would initialize and delete a button that runs a certain macro. Right now, I have a button that is on the toolbar and stays there regardless of what excel file I use. It's unecessary and annoying.
I know that the sub workbook_open and sub workbook_beforeclose have to be used but I'm kinda clueless after that.