The following VBA example selects all extruded shapes whose extrusion depth is more than 20 units.
Sub Test()
Dim s As Shape, eff As Effect
Dim sr As New ShapeRange
For Each s In ActivePage.Shapes
For Each eff In s.Effects
If eff.Type = cdrExtrude Then
With eff.Extrude
If .Type <> cdrExtrudeFrontParallel And .Type <> cdrExtrudeFrontParallel Then
If .Depth > 20 Then
sr.Add s
If Not .ShowBevelOnly Then sr.Add .ExtrudeGroup
If .UseBevel Then sr.Add .BevelGroup
End If
End If
End With
Exit For
End If
Next eff
Next s
sr.CreateSelection
End Sub