Use IBAN number in outbound INVOIC IDOC

Hi,

I'm looking for a field to store the IBAN number in outbound INVOIC IDOC's. Apparently there is no separate field available for this. I would like to avoid extending the current IDOC structure and I would have expected the IBAN number to be part of the SAP standard outbound INVOIC idoc.

Has anyone encountered the same requirement? I have looked at the standard INVOIC01 and INVOIC02 structure.

Thanks

Walter