How to add 2nd icon to custom toolbar.

I have a macro and have placed a toolbar with the single icon.  My single icon executes my macro properly.

Now I would like to add a 2nd icon onto the toolbar so that I may have my macro perform a similar, but slightly different functionality.

What is the procedure to add a 2nd icon to my existing toolbar?

I looked at the original procedure I used to add the initial icon, but see no way to add a 2nd icon.

Thanks in advance,