If it's a custom button, you can write a macropump that looks for the input then when activated, runs the button code. Just copy the button code into the macropump. It wouldn't actually be hitting the button, but rather just running the code behind the button. The end result would be the same.
A brain would be better, if you can do it. VB code is a little more flexible than a brain, but brains execute much faster. Always use a brain if you can.