html in a browser CAN NOT directly open up executable files, as it is a security risk. you can however try a couple of different things:
1) instead of linking directly to the application, such as href="file:///c:\programs\word.exe", you can link to a blank document of the correct type, such as href="file:///c:\programs\blank.doc". then the browser will open the document with the associated program.
2) check out IntraLaunch (http://www.particle.net/IntraLaunch/). it is an activeX control that allows for launching executable files from a browser. here is what their website says:
"IntraLaunch is an ActiveX control for Internet Explorer & Netscape. It is primarily designed for corporate Intranets with Win32 workstations (95/98/NT) that need to use a web browser such as IE to present menus to their end users or employees. It allows HTML links to execute anything from .EXE's to associations such as .DOC's both locally and across a network (HTTP, SMB, etc.).
IntraLaunch can also open several Wizards, a Run dialog box, map network drives, deploy smaller applications, shutdown the workstation as well as many other useful things."
i have not tried this program myself, but several other people i have talked to have said it works as advertised.
just some ideas, if you play around with it some i am sure you can get it to do what you want.