BI 7.0 Connect multiple source systems to a single ECC client ?

Hi experts,

We have a requirement at our client.

Our client has one development client for 2 different companies. They do have 2 QA environments and 2 Production environments, but they are joined in Development.

We want to connect this 2 companies to our BW system. We created one source system connected to the client but we can not create a second source system pointing the same client.

Our Basis team had tested it and they receive the message RSAR201 "Source system <xxx> already exists".

He said that even if you use a different RFC to connect from BW to ECC, you do not have the option to choose a different RFC for the return connection, and you do not have the option to say what source system name you want.

Any ideas to sort this out?

PS: We can NOT create a new client in the source system.

Thanks in advance,

Leticia