I am trying to pass values from VB Script back into a mathcad worksheet but the script is failing to create the worksheet object - vbscript

Question

Can anyone tell me why the activeworksheet object MCWS is not being created by the following VB Script please? It is the code for a combobox in a mathcad worksheet. Thanks
Public Sub SizeBoxEvent_Start()
Dim objEX
Dim objMC
Dim MCWS
Dim objEXWB
Dim objEXWS
Dim intLineNo
Dim objRange
End Sub
Sub SizeBoxEvent_Exec(Inputs,Outputs)
Set objMC = CreateObject("MathCad.Application")
Set MCWS = objMC.ActiveWorkSheet
Set objEX = CreateObject("Excel.Application")
Set objEXWB = GetObject("C:\UB_Dims.xls")
Set objEXWS = objEXWB.worksheets("UB")
Dim MyList(71)
For i = 0 to 71
Mylist(i) = CStr(objEXWS.cells(i+3,1))
'MsgBox Mylist(i)
Next
SizeBox.List() = MyList
intLineNo = SizeBox.ListIndex + 3
objRange = "A" & intLineNo & ":U" & intLineNo
Dim varDimProps(21)
Dim varDimName(21)
For i = 1 to 21
varDimProps(i) = objEXWS.cells(intLineNo,i)
varDimName(i) = CStr(objEXWS.cells(1,i))
Next
MCWS.SetValue "Size", ABC
MCWS.SetValue "M", 288
MCWS.SetValue "D", 203
Outputs(0).Value = varDimProps
End Sub
Sub SizeBoxEvent_Stop()
Rem TODO: Add your code here
End Sub

Answer 1

I haven't used Public subs, so I don't know if your declarations will carry over to other subs. Here's something I picked from the PTC forum that works in Excel 2007 with Mathcad 15.0 (I understand that the excel add in is broken for later excel versions).
My guess is that you should define your objects in the functions that use them. Also, I don't think you can use Activeworksheet for the MathCad worksheet.
Private Function RunMCAD(InputFile As String)
Dim MC As Object
Set MC = CreateObject("Mathcad.Application")
MC.Visible = True
Set Wk = MC.Worksheets
Set WS = Wk.Open("C:\RDDA\RDDA 2014-10-16_excel.xmcd")
WS.SetValue "InputFile", InputFile
WS.Recalculate
WS.Save
WS.Close False
MC.Quit
RunMCAD = "Done"
End Function