Setting up bank cross reference

If we set up bank accounts using P0030A_W0030AE, and we have address book numbers set up for each bank, shouldn't we be able to associate that bank information with vendors without having to re-type banking information?

We go into P0030A Work with bank accounts by address

We click add

We would like to be able to type in the transit number and have the bank address book number filled in that is associated with that transit number

OR

We would like to be able to type in the bank address book number (there is no look up associated with this field) and have it populate the associated transit number