I'm posting this in the hope that someone finds this useful - if you
do, please email me with any comments / suggestions...

I recently had a problem where I needed to access a database on a CD
using just client side VBScript, but I needed the full path to the
database for ADO to find it.  I find a solution by using the following
code....

function GetDriveLetter(byval dURL)
        dim x
        x = instr(1,lcase(dURL),"file:///")
        if x > 0 then
                dURL = replace(lcase(dURL),"file:///","")   'remove file part of line
                GetDriveLetter = left(dURL,2)
        end if
end function

function GetPath(byval pURL)
        dim x
        x = instr(1,lcase(pURL),"file:///")
        if x > 0 then
                pURL = replace(lcase(pURL),"file:///","")   'remove file part of line
                x = instrrev(pURL,"/")
                GetPath = left(pURL,x)
        end if
end function

The functions will return the full path (or just the drive letter) of
the current page, and are designed with file urls in mind.  If a
normal HTTP url is entered, they will return nothing.  The idea should
also work in JavaScript, and if you'd like the same examples in
Javascript, let me know.

Shaun