Assigned Macro Name Does Not Change When Workbook Is Copied And Renamed

I've created a custom toolbar and populated it with a custom button. I have created a macro and it resides in ThisWorkbook. The macro is assigned to the custom button and the toolbar attached to the workbook. So far, so good. If I copy the workbook and rename it, when I click the button to run the macro it launches the original workbook and runs the macro. The macro effects changes on the renamed workbook copy. The macro name found in the assign macro dialogue starts with the original workbook name. The same effect if the macro resides in a module or sheet. Any known way to have the macro name change along with the renaming of the workbook such taht it refers to the currently opened workbook macros? Regards.