IDoc Headerfield Mapping

Hi,

I have a scenario 3rd Party(HTTP)->XI->R/3(IDoc).

I gave the 3rd party business system the logical system "C1Send". So the IDoc reaching the R/3 has the partner type "LS" and the partner no "C1Send". But I need "KU" and "M001".

I should create partners in the integration builder directory and configure the receiver agreement and the communication channel , but I don't understand the concept very well.

For which services I have to create partners?

How are the entries for "Agency", "Scheme" and "Name"?

How to configure the Header Mapping in the Receiver Agreement?

And configuring the IDoc-communication channel: How to fill the field under "Identifiers"?

Thanks a lot for help, Udo