You should not have posted those email addresses here. Web robots can scan forums and grab unsuspecting email addresses for spam.

Regarding your post, I am not entirely sure I understand what you are trying to do.

What is "an aged receivable spreadsheet"?

If a customer is over what? by 30 days?
Less than 60 what?

Try this:

Cell formula =IF(A1<30,B1,IF(A1<60,B2,IF(A1<90,B3,B4)))

If A1 is less than 30, use B1
If not, then if A1 is less than 60, use B2
If not, then if A1 is less than 90, use B3,
Otherwise, use B4.

Mark