One payment medium format for two payment methods

Hi Gurus,

I have created two payment methods for ACH file for two bank accounts (CAD and USD) in one house bank. I have one payment medium format which will be used in these two payment methods.

How will system differentiate these two files and how will bank know that which file is related to CAD or US??? There is only one variant we can assign to payment medium format in OBPM4.

Please reply.

Thank You