RS232 communication

Hi all I want to read a code communication to C51 by RS232,if define constant send as : char dataBuffer[10]={0x02,0xFD}; ComWrt(2,dataBuffer,strlen(dataBuffer)); ComWrtByte(comport, 0x02); ComWrtByte(comport, 0xFD); It's OK . Now I want to use Numberic Control write anyone such(02FD,02FB,0xF7)can identify as define constant(0x02,0xFD),how to converter it .Thanks for your help any!