skill code to add netSet property on an instance (detail)

Dear Sirs,

I have an open schematic with many different instances.
(Cadence IC 5.1.41 Virtuoso Schematic)
How can I add to all the instants a "gdn33" netset with value "VDD" ?
"gdn33" this name netSet the properties.
"VDD" this name net in schematic.
I saw the answer
community.cadence.com/.../10777

But unfortunately my knowledge in the skill is very small.
Could you show the detailed code to solve my problem.

Thanks,
Andrey.