Code:
#ifndef MYLIB_H_
#define MYLIB_H_


#endif /* MYLIB_H_ */

int libmylibfunc1(unsigned char);


Code:
#include "mylib.h"

int
libmylibfunc1(unsigned char cParam)
{
  int rVal = 0;

  rVal = (int)((unsigned int) cParam);
  return rVal;
}
Code:
#include "mylib.h"

int
main(void)
{
  return libmylibfunc1('A');
}
so das dürfte das sein was du brauchst