EXCEL MarcoVBA Navigation Menu

Hi there pro coders,

First, kindly refer to the attached image and lets name it "Navigation menu Bar".
All I want to know is how to do this. I took it from a macro enable excel file.
When I open the said file, a log-in form will pop-up. But lets jud disregard that.

All I want to learn from you is that, When I open a specific excel file, the
"Navigation Menu Bar" Will pop-up and then if I click any of the button, it will
proceed to the assigned worksheet.

I also want to learn how to add button inside the excel file where in if I click, it
will return to "Navigation Menu Bar"

Thank You and More Power