Code:
void writefunc(void){
extern CFile cfile;
typedef struct mything{
  char abuf[100];
  char pbuf[100];
} t, *a;
a=&t;
// assuming you now have data in t
cfile.Write(a->abuf, sizeof(struct mything)  );
cfile.Close;    // write to the file & close it.
cfile.Open;
// read data from the file into a struct.
cfile.Read(a,sizeof(struct mything) );
cfile.CLose;

}