Custom list of things in LaTeX?

I'm writing a script for college where I insert the date of a part of text apart from the chapters using a custom command (currently just displaying a marginpar), like:

\lesson{1}
\section{A}
\section{B}
\subsection{C}
\lesson{2}
\subsection{D}

Apart from the usual \listoffigures, \listoftables and \tableofcontents I want a list that allows access by lesson number. It should look like the \listoffigures except with a custom label (since the lessons don't h开发者_StackOverflow中文版ave captions), for example:

Lesson 1 ..... Page 1
Lesson 2 ..... Page 5

Is there a package that allows me to define new lists like that as easy as creating new counters? Or do I have to dig into the source for the existing lists and hack my own?

(the memoir package documentation has a list of rendered examples at the beginning, that would be another example of a custom list like I need it)

Any keywords to google for are appreciated!

I would do the following:

1) Open a file at the beginning:

\newwrite\listoffoo
\immediate\openout\listoffoo=\jobname.foo

2) Each command like \lesson should put a line into the file:

\newcounter{lesson}
\def\lesson{%
    ...
    \refstepcounter{lesson}%
    \immediate\write\listoffoo{%
        \string\lessonfooline{\ref{lesson}}{\pageref{lesson}}}
    ...
}

3) At the end of the processing, close the file and read it in:

\immediate\closeout\listoffoo
\input\jobname.foo

You'll have to define the commands like \lessonfooline.

Hope this outline helps.