HP SIM 6.0 "global" SSH key

[CoffeeNipper]

Hi,
unfortunately I don't find the right answer for my SSH issue inthe knowledge base.
I have an HPSIM 6 running on Windows 2008. Now I should add also Unix/Linux servers to the Monitoring. Problem is that the servers have different passwords for the root account. Therefore we have an OpenSSH RSA private key we use for authentication (the corresponding public key is already in the authorized_keys file for the user on the Unix/Linux systems). This key is for an Unix account without root access. I'm not an expert in Unix or SSH, but can someone tell me if HPSIM needs root access and if an RSA key is OK, HPSIM maybe require an DSA key, I don't know. Furthermore I want to use the existing key and not the current one from HPSIM, but how can this be changed? If someone can provide a "short" documentation how to configure SSH for an specific rsa key and the corresponding user would be much appriciated.
Thanks