\def\lbshframe #1#2#3#4{\vbox{\hrule height 0pt%
 \hbox{\vrule width #1pt\kern 0pt%               
 \vbox{\kern-#1pt\frame{.3}{#2}{#3}{#4}%      
 \kern-.3pt}%                                    
 \kern-#1pt\vrule width 0pt}%          
 \hrule height #1pt}}

\lbshframe{4}{10}{23pc}{\copy4}\lbshframe{4}{10}{23pc}{\copy4}