Well...I am not sure, but this may just work!!
Right click anywhere on the empty area of the desktop and from the options, select "New Launcher"
Now in the command text-box type the following command
mozilla
http://your-ip-address/~user
OR
mozilla
http://your-web-site-name/~user (will work only if DNS is setup)
[ Note: you may use any browser in place of mozilla ]
Also, fill the other text boxes for Name, description and comments..and if u want, u can also select an icon for this launcher...
Now whenever your user will double-click this icon, it should open his home directory....( if someone feels this is not correct, do correct me pls..)
PS....You have slackware, and I have Red Hat 9...so a right click on the desktop may or may not give you the "New Launcher" option...just check how you can implement this idea on your distro...
Regards,
amit