VBScript.RegExp

a week ago I asked an Excel programming question related to searching for a particular string. Leith Ross provided a solution based on RegExp. I am trying to use this method now for a PowerPoint macro.

I used a PowerPoint macro that I use to remove carriage returns from a textbox and merged in the RegExp code. The result can be seen below.

With this sub I am getting an Object required error message for the replace statement. I have no idea how to code this part correctly. Does anybody know how to debug this line.

Sub DeleteBracketsAndContents()
    Dim oshp As Shape
    Dim otxt As TextRange
     
    Set RegExp = CreateObject("VBScript.RegExp")
    RegExp.IgnoreCase = True
    RegExp.Pattern = "[[]\number.*[]]"
     
     'check for type of selection 
     'replaces all text in shape unless text is highlighted
    If ActiveWindow.Selection.Type = ppSelectionNone _
    Or ActiveWindow.Selection.Type = ppSelectionSlides Then Exit Sub
    If ActiveWindow.Selection.Type = ppSelectionShapes Then
        Set oshp = ActiveWindow.Selection.ShapeRange(1)
        Set otxt = oshp.TextFrame.TextRange
    End If
    If ActiveWindow.Selection.Type = ppSelectionText Then
        Set otxt = ActiveWindow.Selection.TextRange
        If Len(otxt) < 1 Then
            Set otxt = otxt.Parent.Parent.TextFrame.TextRange
        End If
    End If
    
    'Replace text
    With otxt
              '    .Text = Replace(.Text, vbCr, " ")  
              '    The above line removes carriage returns in my PowerPoint macro
              '     I replaced vbCr with Reg.Pattern. It was a wild guess.
          .Text = Replace(.Text, Reg.Pattern, "")         
    End With
    
    Set RegExp = Nothing
    
End Sub