How to perform MAC (Message Authenticate Code) with hashing in .Net CF

Question

 I need to perform MACing using the MD5 algorithm under the .Net Compact framework. I have got code in .Net for desktop version of application but that code is not working in .Net CF.

    HMACMD5 myhmacMD5 = new HMACMD5(key);

   HMACMD5 API is not working in .Net compact framwork. Is there any alternative way to perform the MACing in the .Net CF.