Excel Function or VBA

Hello ,
I would like to write an excel function or a VBA function in Excel, What it will do is:
If the amount in column N is more that zero, Go and look at column D and E and F by choosing the latest date from these three columns and then putting the difference in dates between that latest date and Now in Column B. Hope that it make sense

Thanks for any help .....

sounds like a normal EXCEL entry like:

VB Code:

If (N1>0; Now- (max(D1,E1,F1));empty)

Note: I don'T have EXCEL on hand, so the formatting is definitley false, but you should get the point.

put that code into cell b1

Thank s a million , it did what i intended to have .

thanks