Some properties in the Powerdesigner object model are RTF. Powerdesigner offers a 'RTF2ASCII' function to convert the rich text to plain text. You can use the function by calling the child method from the Powerdesigner.Application Object.
Dim PD As PdCommon.Application
Set PD = CreateObject("PowerDesigner.Application")
NormalText = PD.RTF2ASCII(Ent.Description)