Restricting access to specific files on my network when accessed by wireles

Hi,
Im having a problem at the moment with a classroom manager program that is installed on a central computer on a school network that teachers can access from their laptops. The program’s database is rather large and does not (following advice from the people who wrote the program) like being accessed and modified over a wireless network as it experiences time out errors with the 802.11g 54mbps speed. Is there a way that I can restrict access to either the folder or computer that the database and all its configuration files are stored in so that the program can only be run over a wired network connection??
any suggestions would be appreciated.
Thanx,
John Calder.