How do I change Nudge Distance via VBA


I want to change the nudge distance of my document to the width of selected object.

e.g.: I have rectangle selected which is 7.21mm wide.

I'm trying to write a macro which takes the width of selected rectangle and sets the nudge distance to that value, so that i don't have to remember or copy/paste the numbers.

I'm stuck with setting the nudge value programmatically. 

Thanks and regards.