I would assume that the motherboard has a laptop style 44 pin ide connector then? if so, you can get adapter boards to hook laptop drives to normal ide connectors, i assume this would work in reverse too. On that same note, maybe a normal laptop dvd drive would work as well. As another option, you may be able to pull the hard drive out, install it in a desktop system temporarily, and then do the install.
You may also be able to find guides online for doing a network install of kubuntu, which would give you a way to do the cd install. This starts to get pretty technical though, and requires setting up a server with some very specific software packages. It will certainly involve lots of command line work.