Vista - How to apply changes to "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\Personal" (My Document)?

I developed a small script that changes the key relative to "My Documents"
folder AFTER the user logon.
It is a win2003 server with citrix metaframe, so many user are connected at
the same time (that's why i have to get the right explorer pid to kill)
I noticed that after changing this key, the actual folder pointed by "My
Documents" is not affected unless the user log off and then back on.
Another way to apply the change, beside logging off/on, is to kill
"explorer.exe" and run it again.

This is the code:

Dim WSHShell
Set WSHShell = CreateObject("WScript.Shell")
strComputer = "."

Set objWMIService = GetObject("winMgmts:\\localhost")
Set colItems = objWMIService.ExecQuery("Select * From Win32_Process where
Name='explorer.exe'")
Dim strUserName, strDomain, pid, base

base=WScript.Arguments.Item(0)

For Each objItem in colItems

objItem.GetOwner strUser, strDomain

If (strUser=WSHShell.ExpandEnvironmentStrings("%USERNAME%")) Then
pid=objItem.ProcessID
End If

Next

WSHShell.RegWrite
"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User
Shell Folders\Personal", "w:\firma\"& base
WSHShell.Run "taskkill /pid "&pid&" /f"
WSHShell.Run "explorer.bat" 'runs explorer.exe

But i would like to find a way to apply this change without such brutal
killing.. anyone has an idea on how doing this?

Thank you for your consideration!