I'm not sure what the question is :)
But I'm guessing you want to store the actual Ghost image files (.GHO and .GHS as needed) on your Iomega drive. Sure. But you'll have to mount them on the computer that's actually receiving the image.
So you have an office PC you want to image. You run the Ghostcast Server on your Ghost server. The machine running the Ghost server will have to mount (net use z: \\iomeganetworkdrive\somesharename). Then you can treat the Iomega thing as a normal "local" drive mounted at Z: (choose your own letter of course.) Yes, this means you'll have double the network traffic - the image from the client to the ghost server machine, and then the ghost server machine storing it on the Z: drive (which happens to be a network mounted drive.)
You can also mount the Iomega drive directly on the office PC you want to backup and skip the entire Ghost server thing. Boot the office PC using a Ghost boot disk with networking support. Mount the Iomega drive directly to the office PC (since it has networking support, it can do that.) Then clone from the office PCdirectly to the Iomega network drive, that's mounted on the office PC.
All very doable and works great.
Good luck!
PH