can i add text to rawtobytedata ?

[Madammar]

i have the following code 

Code:

procedure Tform1.rData(Sender: TObject; const Buffer: Pointer;
  BufferSize: Cardinal; var FreeIt: Boolean);
var
Bytes: TIdBytes;
begin


if (Buffer <> nil) and (BufferSize > 0) And (udpreciver.Active) then
begin
udpsender.SendBuffer(ip, port, RawToBytes(Buffer^, Buffersize));
end;

end;

i want to add a text identification to each audio sent and then remove that text when its received 


like following as example 

Code:

if (Buffer <> nil) and (BufferSize > 0) And (udpreciver.Active) then
begin
udpsender.SendBuffer(ip, port, RawToBytes('Audio1'+Buffer^, Buffersize));
end;

how to do this in correct way