In the following "pc" is real host name and "peg" is a virtual host.
Some testings...
/~alice/
. This should jump to alice's page on real host
/
. This should jump to official page of real host
http://peg/~alice/
. This should fail because virtual host has no user
http://pc/~bob/
. This should jump to user bob on pc. (This page)
http://pc/~arisawa/
. This should jump to user arisawa on pc