BIG THANKS to Nick Gammon!
Using Code which post Nick Gammon + I figure out how to use BUF and i get result by myself about what I all time asking from start of this post!!!
Check this out!!!
void setup ()
 {
 Serial.begin (115200);
 unsigned long hexString = 0x1FD3DC;
 unsigned int buf[8];
 int Variable0;
 int Variable1;
 int Variable2;
 int Variable3;
 int Variable4;
 int Variable5;
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 for (byte i = 0; i < 8; i++)
   {
   byte nibble = hexString & 0xF;
   (buf[i]) = nibble; Â
   hexString >>= 4;
   }
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  Variable0 = (buf[5]);
  Variable1 = (buf[4]);
  Variable2 = (buf[3]);
  Variable3 = (buf[2]);
  Variable4 = (buf[1]);
  Variable5 = (buf[0]);
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  Serial.print("V0= ");
  Serial.println (Variable0,HEX);
  Serial.print("V1= ");
  Serial.println (Variable1,HEX);
  Serial.print("V2= ");
  Serial.println (Variable2,HEX);
  Serial.print("V3= ");
  Serial.println (Variable3,HEX);
  Serial.print("V4= ");
  Serial.println (Variable4,HEX);
  Serial.print("V5= ");
  Serial.println (Variable5,HEX);
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 }
void loop () { }