#include <ezbyaplc.h>
char myappldata[SETADBUFLEN+1];       /* extra byte for null string terminator */
SetApplData myIoctlParm;
SetADcontainer myBuffer;

sprintf(myappldata, "@HRSERVR%8.8s%8.8s%8.8s%8.8s", a, b, c,d); /* prefix 
        and 4 char[8] fields */

memcpy(myIoctlParm.SetAD_eye1,SETADEYE1,sizeof(myIoctlParm.SetAD_eye1));
myIoctlParm.SetAD_ver = SETADVER;
myIoctlParm.SetAD_len = sizeof(SetADcontainer);
myIoctlParm.SetAD_ptr = &myBuffer

memcpy(myBuffer.SetAD_eye2,SETADEYE2,sizeof(myIoctlParm.SetAD_eye2));
memcpy(myBuffer.SetADbuffer,myappldata,SETADBUFLEN);

rc = ioctl(soc, SIOCSAPPLDATA, (char *)&myIoctlParm);