Formula Builder query - IsinList

Hi 

I am trying to get a field to become visable on the Quote Module only if the Customer Number selected is equal to a specific number such as 323001419. 

The visability of the field is dependent on a formula. This is the formula i have tried is below 

related($billing_accounts,"pr_account_number_c")isInList(323001419,createList(323001419,323001420)=true.

Its not working for me. Anyone have any ideas?