こんな感じのスクリプトじゃだめなん？

Option Explicit
Dim WshShell, doc, cbstr, restr, oExec
Set doc = CreateObject("htmlfile")
cbstr = doc.parentwindow.clipboardData.GetData("text")
restr = Replace(cbstr, "mx-sh.net", "www.mexashare.com")
Set WshShell = WScript.CreateObject("WScript.Shell")
Set oExec = WshShell.Exec("clip")
oExec.Stdin.Write(restr)
Set doc = Nothing
Set oExec = Nothing
Set WshShell = Nothing