Include AS4 messages in TN from other systems

Hi to everyone,

I’m novice in using TN. We use TN with the package AS4 for exchange information between an heterogeneous system in Europe.
And the issue is related with the messages that other countries give to my system.
When I have to generate a message I use the wm.ip.estd.as4.msh:submit (from AS4) to create the message and put into TN. But, how should I put into TN messages that come from other contries?
I can’t use the wm.ip.estd.as4.msh:submit service, because this service expects data to build the message and I have the built message yet…
Should I have to use the service of TN? In this case I’ll have to create new Document types because the created by the installation aren’t valid for this way of include AS4 messages in TN.

Thanks in advance