Get Around Circular Dependency

I am trying to get around a ciruclar dependancy where I am taking the previous weeks value 

COL1 Takes value from previous week COL 2 and adds to COl3

COL2 -Takes current week COl1 and adds COL 4

Seems like because in COL1, I am refrencing the previous week value from COL 2, it creates a ciruclar depenecnfay even though it works in excel.

Is there a way around this?