Hi!
I am not exactly sure what you mean by the .sasrc file, perhaps you mean the autoexec.sas file??
This Tech Support document of FAQs about library definitions with Enterprise Guide 3.x
http://support.sas.com/techsup/unotes/SN/014/014080.html
may help you get a better idea of how to do what you need to do. Much of what you find in this document will work for EG 4, too.
If this note doesn't help you, then your best bet for figuring out how to get your libnames assigned in EG given your particular system configuration is to contact Tech Support:
http://support.sas.com/techsup/contact/index.html
If you are not using EG 3, then Tech Support can help you figure out the correct library assignment method for EG 4, too.
Good luck,
cynthia