RunDLL32.EXE shell32.dll,ShellExec_RunDLL "ドキュメントのパス"

	Set WSH = CreateObject("WScript.Shell")

	strReg = WSH.RegRead("HKCR\Excel.Application\CLSID\")
	strReg = WSH.RegRead("HKCR\CLSID\" & strReg & "\LocalServer\")
	strReg = Replace( strReg, "/automation", "", 1, -1, 1 )
	strReg = Trim( strReg )
	strReg = """" & strReg & """" & " " & """" & TargetExcel & """"
	Call WSH.Run(strReg)

	Set WSH = Nothing

9x では以下でも OKだと思います

RunDLL32.EXE url.dll,FileProtocolHandler index.html