Lazarus XML editor (creating a new line from an existing file path string)

procedure Gaseste(const fileName, searchText,ext: string;var nr:integer);   //procedure to find every game in the list
var                               //search will include parameters: file name, file extension
  sl: TStringList;
  i: Integer;
  NumeleImaginii:string;        //image name
begin
  sl := TStringList.Create;
  nr:=0;
  try
    sl.LoadFromFile(fileName);    //loading string list from file
    NumeleImaginii:='';
    for i := sl.Count-1 downto 0 do
    begin
      if Pos(searchText, sl[i])<>0 then    //for every line we look for a string of interest containing searchText
      begin
        NumeleImaginii:=sl[i].Remove(0,18); //delete from file path the first characters: <path>./
                                             //I will use sl[i].Delete. For some reason removing 18 characters from the string
                                             //results in less characters removed
        Form1.Caption:=Form1.Caption+' '+NumeleImaginii;  //just checking what I deleted from my string

        NumeleImaginii:=NumeleImaginii.Remove(NumeleImaginii.Length-11,11);   //delete from file path the last 10 characters
                                                                              //that also include file extension ***</path>


        sl.Insert(i,'        <image>./Covers/'+NumeleImaginii+'.png</image>'); //insert the image name in the XML
        nr:=nr+1;
        //sl.Delete(i);
      end;
    end;
    sl.SaveToFile(fileName+'.edit');     //saving filename.edit
  finally
    sl.Free;
  end;
end;