Hi,
May I second Craig's view.
I do run servers at this stage, only workstation stuff. But I'd NEVER run server-based Excel, what its qualities may be.
When its comes to running robust server-based MS-Excel building and automation from the good ol' fox, there not so many dotnet-free solutions. I'd recommend you check the link below. Do not be fooled by the website and company size, this small shot delivers robust server-side solutions for Ms-Excel.
http://xlsgen.arstdesign.com/Daniel