Is it possible to link the thickness of a sheet metal part to a global variable?

Normally thickness is a global variable which is grayed out in the list of variables and it can't be changed or calculated.

We have to right click Sheet_Metal feature in the tree and select Edit and input a number in thickness textbox to change it.

Is it possible to link this value to a global variable? somehow that the thickness reads it's value from a calculated variable instead of a number?

thanks for any kind of advice and help