How to concatenate hex byte array to long int without using union in C?

Question

I have an array.Array Bytes are in hexadecimal.Now I am trying to concatenate array index 1 to 4 in to unsigned long int and 5 to 8 in to one more unsigned long int and index 9 and 10 to unsigned int. I tried like this. But its not working.I do not want to use union to concatenate. I am using this code in STM32F4-Discovery.

This is a receive interrupt Handler function :

  void usart1_IRqHandler()
  {
  unsigned char received_string[20];
  unsigned long int Addr1=0,Addr2=0;
  unsigned int Addr=0;

  /*Code to Receive Entire packet.......
   .....................................
   .....................................
  At this point whole packet is received, now I want to send back the response to the target node using address from received data, So first step is to concatenate address bytes*/ 

  /*From the logic analyzer I can observe the received_string bytes as shown below 
  received_string[1]=0x00; 
  received_string[2]=0x13;
  received_string[3]=0xA2;
  received_string[4]=0x00;

  received_string[5]=0x40;
  received_string[6]=0xB4;
  received_string[7]=0x14;
  received_string[8]=0x35;

  received_string[9]=0x8E;
  received_string[10]=0xC7;*/

  Addr1 =  (received_string[1]<<24)| (received_string[2]<<16)| (received_string[3]  <<8)| received_string[4]);
  Addr2 =  (received_string[5]<<24)| (received_string[6]<<16)|(received_string[7]  <<8)| received_string[8]);           
  Addr =  (received_string[9]<<8)| (received_string[10]);   

  Send_packet(Addr1,Addr2,Addr);
  }

Function Send Packet will target remote node with these address.

     Send_packet(unsigned long int Addr1,unsigned long int Addr1,unsigned int Addr)
    {
      unsigned char tx_buf[20];
      tx_buf[5]=(Addr1>>24) & 0xff;
      tx_buf[6]=(Addr1>>16) & 0xff;
      tx_buf[7]=(Addr1>>8)  & 0xff;
      tx_buf[8]=(Addr1>>0)  & 0xff;

      tx_buf[9]=(Addr2>>24)  & 0xff;
      tx_buf[10]=(Addr2>>16) & 0xff;
      tx_buf[11]=(Addr3>>8)  & 0xff;
      tx_buf[12]=(Addr4>>0)  & 0xff;

      tx_buf[9]=(Addr2>>8)  & 0xff;
      tx_buf[10]=(Addr2>>0) & 0xff;

      usart_send(tx_buf);

   }

This is the out put of Sending packet in logic analyzer.

  Addr1=0xA2401437
  Addr2=0x025500A2
  Addr=0x4014

Since the address does not matched, I cannot able to target the remote node.

Answer 1

int i = ((received_string[0] << 24) & 0xff000000) |
                ((received_string[1] << 16) & 0x00ff0000) |
                ((received_string[2] << 8) & 0x0000ff00) |
                ((received_string[3] << 0) & 0x000000ff);

This will construct the unsigned int for you. You can change the indexes of my example to your desired indexes