Hi!
As I understand, you are trying to connect the front panel connector and has question about it goes integrated. If I infer correctly, I'd recommend referring to
Connector Pin-out (J1E1):
You could find the Service Guide very useful, as well:
Intel® Server Chassis P4304XXS — Intel® Server Chassis P4000S Family Service Guide
If you would still need further assistance, I'd appreciate if you could, please, provide more insight as to what extra connector that is you refer to.