Changing from one metal layer to another metal layer

Is this something you wish to do repeatedly or just a one-off? If it's a one-off I'd just use the ui.

I would like to change the metal layers inside the PR boundary only. Like outside the PR boundary I dont want to change the layer 

That doesn't answer the question.

N.B Area select entirely feasible.

This thread from a previous question goes part of the way...

Skill code to copy object to another metal layer but maintain the objects purpose - Custom IC SKILL - Cadence Technology Forums - Cadence Community

I would like to do it repeatedly and moreover one thing we can do change change metal layer "X" to metal "Y" within a specific area (coordinate location)

I would like to do it repeatedly and moreover one thing we can do change change metal layer "X" to metal "Y" within a specific area (coordinate location)