LaTeX 宏在方程式中展开

Question

equation使用时如何扩展用户定义的宏htlatex？我的 LaTeX MWE 是：

\documentclass{article}
\usepackage{amsmath,amsfonts}
\newcommand\EquationAlt[1]{#1}
\def\alp{\alpha_{zzz}^{xxx}}
\begin{document}

Sample $a$ Paragraph $a+a1$ text $a+b_{234}$ with $\alpha+\beta^{\gamma}$ Inline Equations \EquationAlt{$\frac{1}{2}$}.

\EquationAlt{\begin{equation}
\label{eq3}
\alpha + \beta = \gamma
\end{equation}
}

and Eq.~\ref{eq1}

\EquationAlt{\begin{equation*}
\Omega + \zeta = \iota
\end{equation*}
}

so $\alp$ that Equation.\ref{eq3} etc..

\EquationAlt{\begin{equation}
\label{eq1}
\Gamma + \epsilon = \varepsilon \hbox{ and } \alp
\end{equation}
}
\end{document}

我的 tex4ht 配置文件是：

\Preamble{html}
\newtoks\eqtoks 

\def\EquationAlt{\afterassignment\setimg\eqtoks}  
\def\setimg{\Picture*[\expandafter\HCode{\expandafter\the\eqtoks}]{}\the\eqtoks\EndPicture}  

\def\SubSupOp#1{%  
\edef\temp{\expandafter\gobble\string#1}%  
\expandafter\let\csname old\temp\endcsname=#1  
\edef\temp{\noexpand\SUBSUPOP{\expandafter\noexpand  
\csname old\temp\endcsname}}%  
\HLet#1=\temp  
}  
\def\gobble#1{}  
\def\SUBSUPOP#1{\let\curOP=#1%  
\let\next=\putOP \let\OPsub=\empty \let\OPsup=\empty  
\futurelet\nextop\getOP}  
\def\getOP{%  
\ifx _\nextop \let\next=\getsub  
\else\ifx ^\nextop \let\next=\getsup\fi\fi \next}  
\def\getsub#1#2{\def\OPsub{#2}\let\next=\putOP  
\futurelet\nextop\getOP}  
\def\getsup#1#2{\def\OPsup{#2}\let\next=\putOP  
\futurelet\nextop\getOP}  
\def\putOP{\Picture+{  align="middle"}{\curOP_{\OPsub}^{\OPsup}}\EndPicture}  

\SubSupOp\sum  
\SubSupOp\int

\begin{document}
\EndPreamble

等待你的回复。