\noindent
\setbox1=\hbox to 2000000sp{$p$\hfill$q$}%
\pdfxform 1%
\hbox to 1000000sp{XX}%
\pdfrefxform\pdflastxform%
\hbox to 1000000sp{YY}%
\noindent \hrule height 200000sp
\noindent\leavevmode
\setbox2=\vbox to 1000000sp{\hbox to 2000000sp{$p$\hfill$q$}}%
\pdfxform 2%
\hbox to 1000000sp{XX}%
\pdfrefxform\pdflastxform%
\hbox to 1000000sp{YY}%

\end