It sounds like his solution may not be web based. Could he not have employees dialing in to his server directly, and executing the programme that way?
A program called "Citrix" could also perform the function, and that can be configured to operate via a web browser - check out
http://www.citrix.com/ for more details.
The alternative is to build your own "version" of his system, using asp/mssql , php/mysql , coldfusion or whatever - that would make things 100% web based, but may not be the best solution here.
H