对 @u101077 的答案做了一点小优化
\documentclass{ctexart}
\usepackage[a4paper, margin = 2cm]{geometry}
\pagestyle{empty}
\newfontfamily{\XWWKen}{LXGW WenKai}
\makeatletter
\newcount\@tmp@cnt
% #1: number
\def\@zheng@symbol#1{%
\begingroup
\XWWKen
\ifnum#1>5\relax%
\@zheng@symbol{5}%
\@tmp@cnt=#1\relax
\advance\@tmp@cnt by - 5\relax%
\expandafter\@zheng@symbol\@tmp@cnt%
\else
\edef\@tmp@chr{\numexpr#1+1\relax}%
\edef\@@tmp@chr{"1D37\the\@tmp@chr}%
\symbol{\@@tmp@chr}%
\fi
\endgroup
}
\let\zhengsymbol\@zheng@symbol
\def\zheng#1{\expandafter\@zheng@symbol\csname c@#1\endcsname}
\makeatother
\begin{document}
\section{巴拉巴拉}
\zhengsymbol{1},
\zhengsymbol{3},
\zhengsymbol{5}
这是第 \zheng{section} 节
\section{巴拉巴拉}
这是第 \zheng{section} 节
\section{巴拉巴拉}
这是第 \zheng{section} 节
\section{巴拉巴拉}
这是第 \zheng{section} 节
\end{document}
问 如何实现正字计数法的效果?