Mine

#include <dos.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <process.h>

void main( void )
{
#if 0
    putenv( "HELLO=WORLD" );
//    putenv( "CMDLINE=\"This is the real command-line.\"" );
    /*printf( "Errorlevel = %i\n",*/ _exec( "TEST1.EXE", " \"Hello, World.\"" )/* )*/;
#else
    char *argv[] = { "TEST1.EXE", "Hello, World." };

    putenv( "HELLO=WORLD" );

    spawnv( P_WAIT, "TEST1", argv );
#endif
}