Revalue House Bank balance

We are in SAP 6.0 and use T-Code FAGL_FC_VAL to revalue our FX balances.
We have been successful in activating this for our Open Item Managed (OIM) cash accounts but have not been able to get the House Banks included in the process. We have several accounts with a bank account currency different than the entity's local currency. We have added the Valuation Group to FS00 yet we are now receiving a new error (FR887) in FAGL_FC_VA stating "You want to valuate balances in the general ledger. However, the system cannot assign a ledger group to the valuation area. This connection is necessary for the program to read the balances from the correct ledger(s)."
Can you help guide us to where we can assign a Ledger Group to the Valuation Area?