cookie encoding/decoding

I have a situation where a cookie is being set elsewhere on a site by ASP.NET, and I want to read it in my PHP. However, when getting a cookie in PHP, it does an automatic urldecode (or some kind of decoding). Since the cookie is entered in its pure form, with no encoding, on the ASP.NET side, PHP is actually converting/decoding correct characters that don't need decoding. So, for example a plus sign would become a blank space. This, of course, means I'm getting incorrect info from the cookie. Is there a way to turn off this PHP "feature"? Perhaps a flag in the .ini file? -Jeff