Second Client Certificate in HCI for C4C Authentication

Hello,

I'm having a bit of trouble with the HCI to C4C Client authentication in a 2 Systems Setup.

As we have 2 ECC Backends we need to have seperate Communication Arragnements with different Technical Users.

Of course the by HCI provided Client Certificate can be used only for one of those users.

So my question is, how do I get a second certificate for the second user?

Can I simply download the existing Key Pair of the User from C4C and ask SAP Support to import it into HCI, or do I need to get a "real" certificate signed by a real CA?

Thanks for your input.

Tobias