Possible configuration.
\input TeX4ht.sty
\Preamble{html} ... \EndPreamble
\input ProTex.sty
\AlProTex{extension,<<<>>>,list,title,escape-character}
The escape-character stands for `, @, |, or ?. If omitted, it stands for `\'.
\<....\><<< ............ >>>
`<.....`>
\OutputCode\<...\>