As I know there is website called as code convert but that convert VB code in to C# but I think it is not that straight forward in case of matlab to C conversion....as Matlab written code many times uses in-built matlab function like plot() or fft etc. those libraries as I know are developed in Java which is object oriented language where are conversion to structured language like C will be very complicated assignment to write..... In my view what you should do isolate the logic and use minimum matlab in-built function .... and then better to write the code in C itself.....now the second point that you have is you want to use this code to embedded platform like DSPIC which comes with different way of chip specific coding..... so I think even you convert the C code from Matlab file will not be directly used on embedded platform....
Good Luck