Advanced filter to hide records using a formula

[bensko]

I'm using the following formula to count multiple instances of a customer as 1, but how could I use something similar to hide all instances of a customer if one of the rows in a different column meets a certain criteria.

SUM(IF(FREQUENCY(MATCH(AM9:AM986,AM9:AM986,0),MATCH(AM9:AM986,AM9:AM986,0))>0

Column C lists 978 equipment installation project numbers.

Column H is a lookup formula that if a parts order has been placed against that project in the past year, the cell shows "< 1year"

Column K are dates that indicate when we have made the last sales call with that customer

Column AM lists 511 unique customers (more than 1 project was done for several customers)

I'm currently using the following code to hide projects where they have either placed an order with us, or we have made a sales call to that customer in the past year.

Sub ACTIVE_CUST_FILTER()
    Selection.AutoFilter Field:=8, Criteria1:="<>< 1year", Operator:=xlAnd
    Selection.AutoFilter Field:=9, Criteria1:="OPERATING"
    Selection.AutoFilter Field:=11, Criteria1:=">7/23/2008", Operator:=xlAnd
End Sub

I would like the filter to hide all instances/rows of a customer if an order had been placed against 1(or more) projects for that customer. In other words if we have 3 systems for the same customer and they buy parts for one of the systems, I would like all 3 rows to hide.

Would also be nice if someone makes a sales call to a customer and forgets to place the call date in all instances for that customer, the filter is applied to all instances. This one is not a big deal as I try to monitor the workbook for these types of oversights...

Also How can I change (Selection.AutoFilter Field:=11, Criteria1:=">7/23/2008") to >today()-365? can't seem to get that to work?

Thanks for any help in advance,

Ben