We receive Positional Flat File from trading partner using Generic-File-1.0 or Generic-FTP-1.0 listening channel. We don't want to use Name of trading partner (eg. "MarketInc"). Istead we would like to use some other custom identifier and configure it on each trading partner. So that for example partner named "MarketInc" will have "someCustomId" with value "12345". We would like to use this "someCustomId" in Java Callout to map value "12345" to parnter "MarketInc" so that agreement would be correctly identified. Has anyone tried this?