\newbox\msabox
\newdimen\msaw
\font\msaa=msaa
\setbox\msabox=\vbox{\hbox{%
\msaa !(}}
\msaw=\wd\msabox
\setbox\msabox=\hbox{\vbox{\hsize=\msaw
\parskip=0pt\offinterlineskip\parindent0pt
\hbox{\msaa !(}
\hbox{\msaa )+}}}
\ifx\parbox\undefined
    \def\setmsa{\box\msabox}
\else
    \def\setmsa{\parbox{\wd\msabox}{\box\msabox}}
\fi
