c# PropertyInfo extract inner expression

I have to use reflection to cycle through some properties of a reflected object, and collect their PropertyInfo objects.

Some of those properties are of type Expression<Func<Type1,string>>, and I have to extract the underlying Expression from the property info.

I tried myPropertyInfo.GetValue(parParameter) as LambdaExpression but it does not seem to work.

Can anyone give me some pointers?