How could I expess a formula that will show -3 days from a certain
date, but if the answer is a weekend date then it must return the
previous friday

Example: Cell A2= 15/11/07, I must return -3 days from this is A1, but
this = 11/11/07 which is a weekend date, thus I require an answer of
09/11/07 i.e. a Friday

Thanks