uses 
  ClipBrd; 

procedure StrToClipbrd(StrValue: string); 
var 
  S: string; 
  hMem: THandle; 
  pMem: PChar; 
begin 
  hMem := GlobalAlloc(GHND or GMEM_SHARE, Length(StrValue) + 1); 
  if hMem <> 0 then 
  begin 
    pMem := GlobalLock(hMem); 
    if pMem <> nil then 
    begin 
      StrPCopy(pMem, StrValue); 
      GlobalUnlock(hMem); 
      if OpenClipboard(0) then 
      begin 
        EmptyClipboard; 
        SetClipboardData(CF_TEXT, hMem); 
        CloseClipboard; 
      end 
      else 
        GlobalFree(hMem); 
    end 
    else 
      GlobalFree(hMem); 
  end; 
end; 

function GetStrFromClipbrd: string; 
begin 
  if Clipboard.HasFormat(CF_TEXT) then 
    Result := Clipboard.AsText 
  else 
  begin 
    ShowMessage('There is no text in the Clipboard!'); 
    Result := ''; 
  end; 
end; 


// write "Hallo" to the clipboard and read it back. 

procedure TForm1.Button1Click(Sender: TObject); 
begin 
  StrToClipbrd('Hallo'); 
  ShowMessage(GetStrFromClipbrd); 
end;