Reading an IP Address from a flat text file

I know this isn't terribly difficult, but I am having trouble implementing this.

What I am trying to do is read an IP address from a file and then extract the 4 IP fields and assign them to their corresponding fields (a0,a1,a2,a3).  The IP address file is a flat text file with a single line of code.  It appears as such:

"192.168.0.0"

So I can read in the IP address using the CFile read function, but I am having trouble in extracting the four fields and assigning them the the respective field.

I am able to extract the fields by casting "buffer" (char buffer[256]) to a CString and using the CString functions, but I am having trouble assigning that CString that I extract to a BYTE.  I tried to use the BYTE class valueOf function to convert from CString to BYTE, but I was unsuccessful.

Here is the code snippet.  Down below where I say
        // EXTRACT IP INTS FROM BUFFER TO
        // BYTES a0,a1,a2,a3 HERE
is what I need help filling in.

Any help is greatly appreciated.



// beginning code snippet

// GET IP ADDRESS
CFile IPFile;

// Open the IP address file for reading.
if (IPFile.Open("IPAddr.txt",
    CFile::modeRead | CFile::shareDenyWrite))
     {
     BYTE buffer[256];
     DWORD dwRead;
         
     // Read in 4096-byte blocks,
     // remember how many bytes were actually read.
     dwRead = analyzerIPFile.Read(buffer, 256);
     analyzerIPFile.Close();
         
     // declare fields for ip address
     BYTE a0, a1, a2, a3;
         
        // EXTRACT IP INTS FROM BUFFER TO
        // BYTES a0,a1,a2,a3 HERE



     // set IP Address data bytes
     m_pMyObject->setIPBytes(a0,a1,a2,a3);
     }
// end code snippet