As others have pointed out, this is not really possible. Perl and .NET are vastly different beasts and a direct automated conversion simply isn't going to happen. It's difficult enough to have an automated conversion between two languages using the same framework, let alone two languages from entirely different eras that approach web development in entirely different ways.
It should be noted that machine translation is generally as bad in programming languages as it is in spoken languages. Even if it produces something that can be parsed and understood by that language's interpreter, that doesn't mean it's going to actually make sense in that language. (Basically, you'd be getting the C# version of "Engrish.") It would be trying to fit the design considerations of the source language into the syntax of the target language, which is generally a bad idea. The resulting code would likely be more difficult to support and more prone to bugs/exploits/problems than just continuing to support the original code.