1 - Run the project in freeMaster

2 - Create .vbs file in the work area as follows:
'-------------------------------------------------------------------------
Option Explicit
'On Error Resume Next
Dim FMObj
Dim succ
Dim tValue
Dim vValue
Dim bsRetMsg
tValue = 0
Set FMObj = CreateObject("MCB.PCM")
succ = FMObj.ReadVariable("var_test_count", vValue, tValue, bsRetMsg)
WScript.Echo tValue
WScript.Quit
'-------------------------------------------------------------------------
In my case saved as teste.vbs
Note that this very similar to yours.
3 - Run the .vbs file and in my case the result was:


See if that helps.