#pragma linkage (cobrtn,COBOL)
#include <stdio.h>
void cobrtn (char*);

int main()
{
  char x;
  x='a';
  cobrtn(&x);    /* x by reference */
}

IDENTIFICATION DIVISION.
PROGRAM-ID. COBRTN.
ENVIRONMENT DIVISION.
DATA DIVISION.
LINKAGE SECTION.
01 X PIC X.
PROCEDURE DIVISION USING X.
       DISPLAY X
       GOBACK.
END PROGRAM COBRTN.