Find Replace Text within PowerPoint text box?

I can select the textbox from the desired slide, but what am I missing to actually action the function?

    pptPres.Slides(22).Select
    For Each pptShape In pptPres.Slides(22).Shapes
    With pptShape
        If .HasTextFrame Then
        .TextFrame.TextRange.Select
        .TextFrame.TextRange.Replace(FindWhat:="[ClientName]", _
        Replacewhat:=Sheets("SourceData").Range("B1").Value, _
        WholeWords:=True) 'Compile error here expected: "="
        End If
    End With
    Next