To relate a web_domain with a client we need to use the function: client_get_groupid.
Thanks so much M. Piscaer.
That's the function that I was looking for.
I'm doing some tests, and I can see that if all database params are setted, dosen't matter if I don't put a value for client_id...
It works for me.
I'm using the SOAP API, and I want to get the client_id from an existing web_domain.
But I don't found the combination to do that....
Separate names with a comma.