You're welcome, Hamish - thanks for feeding back.

Pete

On May 15, 2:00*pm, Hamish wrote:
Well thats working fine.

So now that im not using INDIRECT, the AND works perfectly and I can do this:
I now have two rules:
=AND((MOD(COLUMN(),4)=1),(D41=MIN($E41,$I41,$M41,$ Q41,$U41)))
and
=AND((MOD(COLUMN(),4)=3),(D41=MAX($G41,$K41,$O41,$ S41,$W41)))

It is however strange that the AND breaks down when one tries to pass an
INDIRECT as one of its arguments.

Thanks very much for your help.