right linq expression

gistfile1.cs

public Expression Right(string value, int targetLenght)
{
  var valueConstant = Expression.Constant(value);
  var targetLenghtConstant = Expression.Constant(targetLenght);
  var pi = typeof(String).GetProperty("Length");
  var mi = typeof(string).GetMethod("Substring", new[] { typeof(int), typeof(int) });

  var valueLenght = Expression.Property(valueConstant, pi);
  var startIndex = Expression.Subtract(valueLenght, targetLenghtConstant);
  var rightExpression =  Expression.Call(valueConstant, mi, startIndex, targetLenght);
  return rightExpression;
}