Animate Text ? Seconds delay between letters

I?m trying to set up an interactive sequence item that displays characters one letter at a time. The code below works well to achieve this, but does anyone know how to set ?seconds delay between letters? (or words - or % delay between letters if another msoAnimEffect is chosen). I seem to be able to set every timing/animation feature except this one!!!

Any help would be very much apreciated.

Nige.

Code:

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Sub aaa()
Dim ISEff As Effect
Dim MyWord As Shape
With ActivePresentation.Slides(2)
    Set MyWord = .Shapes(1)
    Set ISEff = .TimeLine.InteractiveSequences.Add _
    .AddEffect(Shape:=.Shapes(2), effectId:=msoAnimEffectAppear, _
    trigger:=msoAnimTriggerOnShapeClick)
    ISEff.Timing.TriggerShape = MyWord
    Set ISEff = .TimeLine.InteractiveSequences(1) _
    .ConvertToTextUnitEffect(Effect:=ISEff, _
    Uniteffect:=msoAnimTextUnitEffectByCharacter)
End With
End Sub

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