How to cut out a part from a stream in Delphi7

I have an incoming soap message which in in the form of a TStream (Delphi7), server that sends this soap is in development mode and adds a html header to the message for debugging purposes. Now I need to cut out the html header part from it before I can pass it to soap converter. It starts from the beginning with 'pre' tag and ends with '/pre' tag. I'm thinking it should be fairly easy to do, but I haven't done it before in Delphi7, Can someone help me?

I think the following code would do what you want, assuming you only have one <pre> block in your document.

function DepreStream(Stm : tStream):tStream;
var
  sTemp : String;
  oStrStm : tStringStream;
  i : integer;
begin
  oStrStm := tStringStream.create('');
  try
    Stm.Seek(0,soFromBeginning);
    oStrStm.copyfrom(Stm,Stm.Size);
    sTemp := oStrStm.DataString;
    if (Pos('<pre>',sTemp) > 0) and (Pos('</pre>',sTemp) > 0) then
      begin
        delete(sTemp,Pos('<pre>',sTemp),(Pos('</pre>',sTemp)-Pos('<pre>',sTemp))+6);
        oStrStm.free;
        oStrStm := tStringStream.Create(sTemp);
      end;
    Result := tMemoryStream.create;
    oStrStm.Seek(0,soFromBeginning);
    Result.CopyFrom(oStrStm,oStrStm.Size);
    Result.Seek(0,soFromBeginning);
  finally
    oStrStm.free;
  end;
end;

Another option I believe would be to use an xml transform to remove the unwanted tags, but I don't do much in the way of transforms so if anyone else wants that torch...

EDIT: Corrected code so that it works. Teaches me for coding directly into SO rather than into the IDE first.