Hi Kumar
Assuming that you will implement IHC for headqueater server together with its Financial accounting in the same server, you need to configure IHC configuration in Headquater server, while IHC related configuraiton for subsidiaries, including IHC house bank, Payment configuration and Finsta Bank statement in each of Subsidiary server. In case of multiserver landscape, you need to set ALE configuration in a way for IHC headqueater server to communicate to each subsidiary system - WE20 (Partner type B and LS). You would need a bit of testing to ensure that you can achieve this.
With regard to your second question: EBS for IHC will identify the counterparty bank account where that information is included in the Bank statement. When I implemented this with SWIFT MT940 (field 86 structured), our bank then sent the counterparty bank account info in subsection 30 and 31 in field 86, which can then be read by IHC, so this is the prerequisite and then you will be able to include that counterparty information in IHC configuration as above thread.
Hope that this helps you
Regards
Taro