Mounting ISO image on VMware ESX guest OS without VMware client

I am not sure exactly why you say mounting the iso with the VIC client would be over the network, maybe I am misunderstanding how you mean you would be mounting it. But in any case, if you go into "Edit Settings" on the machine on the CD/DVD drive tab there is an option to use "Datastore ISO file". This will let you connect to the ISO on the EX server, and is independent of the VIC client window, meaning once you save the setting you can close the client and the ISO will still be accessible. I have several servers running boot CDs setup like this.

vmware-cmd blabla.vmx setconfig ide0:0.fileName cdrom.iso is supposed to do that

http://www.vmware.com/pdf/Scripting_API_215.pdf

Page 117 is your need, and for the ISO path you'd use /vmfs/volumes/XXXX/ where XXXX is the actual volume storage you're looking for; in my case I have two standalone servers that use their own internal RAID arrays, so the symlink is /vmfs/volumes/SERVERNAME:storage1/ that gives me the root (I store my iso files under a /iso/ subdir).