return char from c++ module to rpg module

I have a C++ proc that returns a "char" to an rpg proc.  It works on paper,
but in practice the rpg proc is always receiving x'00' as the return
variable.

When I return an "int", the return value is received ok.

Does anyone know how to return a "char" from C to RPG?


Here are the C functions:

int  ReturnInt( )
  {
  int  nVlu ;
  nVlu = 25 ;
  return nVlu ;
  }

char ReturnChar( )
  {
  char  ch ;
  ch = 'a' ;
  return ch ;
  }

and the rpg prototypes:
d ReturnInt       pr        10i 0 extproc('ReturnInt__Fv')
d ReturnChar      pr         1a   extproc('ReturnChar__Fv')

and the rpg code:
d ch1             s          1a
d int             s         10i 0
 /free
      ch1         = ReturnChar( ) ;
      int         = ReturnInt( ) ;
 /end-free

When I run this code ch1 contains x'00' when it should have 'a' and int
contains the correct value of 25.

thanks,
Steve Richter