Dim WshShell
Set WshShell = CreateObject("WScript.Shell")
WshShell.Run("script2.vbs")

<package>
    <job id="Main">
        <script language="VBScript" src ="subs.vbs">
           WScript.Echo "Calling subs from subs.vbs"
           Sub1
           Sub2
        </script>
    </job>
</package>

SUB Sub1
  MsgBox "Hello from Sub 1"
END SUB

SUB Sub2
  MsgBox "Hello from Sub 2"
END SUB

dim f, sz 

Set f = CreateObject("Scripting.FileSystemObject")

set sz = f.OpenTextFile("foo.vbs")

execute sz.ReadAll()

msgbox "from foo.vbs"