How can I avoid copy & paste of cells with conditional formatting to mess up
and extend the rules list when pasting?

I copy a cell with conditional formatting from a "template" (it has 3
rules). All I want is to paste that to OVERWRITE the existing format rules
in my destination cells with the ones from the template. Instead, it ADDS
the rules from my template to the existing list of rules ?!? Eaching time I
change the rules in the template and paste them to the destination files,
they all end up with 6 rules, then 9, then 12...

I can I avoid this without having re-correct each single cell in each of my
files I copy my template to?

Thankx for your help