[AUCTeX] defining custom sections?

[Peter Horst]

Following the LaTeX Companion, p. 31, I defined a new subsection style, 
as follows:

\makeatletter
address@hidden
 {0pt}{2.0\baselineskip}{1.0\baselineskip}%
 {\hrule\medskip\raggedright\bfseries\large}}
\makeatother

Can AUCTeX be convinced to treat this "Hsub" subsection as a normal 
\subsection{}, prompting for a subsection label and setting off the 
subsection title in larger text within the .tex document? I saw in the 
docs that AUCTeX can recognize custom environments, but wasn't sure if 
this applied to custom sections.

Thanks much -