get the HTML-Help Workshop from
http://msdn.microsoft.com/library/en-us/htmlhelp/html/vsconHH1Start.asp
(file HTMLHELP.EXE)

create a hhvars.bat
@echo off
echo Setting environment for using HTML Help Workshop.
PATH=%PATH%;"C:\Program Files\HTML Help Workshop"

(add it to your cygwin.bat)

copy
  c:\Program Files\HTML Help Workshop\INCLUDE\*.* in VC98\Include\
  c:\Program Files\HTML Help Workshop\LIB\*.* in VC98\Lib

The user does not need the entire HTML Help Workshop to view a .chm file,
only a runtime called "Help Viewer" that can be downloaded (file: HHUPD.EXE)
from the same URL (also available in C:\Program Files\HTML Help
Workshop\REDIST). Can be freely redistributed.


HTML Help File Formats
----------------------
info found at:
http://parthe.lpthe.jussieu.fr/~zeitlin/wxWindows/docs/wxwin495.htm#helpformat


Help Files Format
wxHTML library uses a reduced version of MS HTML Workshop format. Tex2RTF can 
produce these files when generating HTML, if you set htmlWorkshopFiles to true 
in your tex2rtf.ini file.
(See wxHtmlHelpController for help controller description.)
A book consists of three files: header file, contents file and index file. You 
can make a regular zip archive of these files, plus the HTML and any image 
files, for wxHTML (or helpview) to read; and the .zip file can optionally be 
renamed to .htb.
Header file (.hhp)
Header file must contain these lines (and may contain additional lines which are 
ignored) :
Contents file=<filename.hhc>
Index file=<filename.hhk>
Title=<title of your book>
Default topic=<default page to be displayed.htm>

All filenames (including the Default topic) are relative to the location of .hhp 
file.
Localization note: In addition, .hhp file may contain line
Charset=<rfc_charset>

which specifies what charset (e.g. "iso8859_1") was used in contents and index 
files. Please note that this line is incompatible with MS HTML Help Workshop and 
it would either silently remove it or complain with some error. See also Writing 
non-English applications.
Contents file (.hhc)
Contents file has HTML syntax and it can be parsed by regular HTML parser. It 
contains exactly one list (<ul>....</ul> statement):
<ul>

  <li> <object type="text/sitemap">
           <param name="Name" value="@topic name@">
           <param name="ID" value=@numeric_id@>
           <param name="Local" value="@filename.htm@">
       </object>
  <li> <object type="text/sitemap">
           <param name="Name" value="@topic name@">
           <param name="ID" value=@numeric_id@>
           <param name="Local" value="@filename.htm@">
       </object>
  ...    

</ul>

You can modify value attributes of param tags. topic name is name of 
chapter/topic as is displayed in contents, filename.htm is HTML page name 
(relative to .hhp file) and numeric_id is optional - it is used only when you 
use wxHtmlHelpController::Display(int)
Items in the list may be nested - one <li> statement may contain a <ul> 
sub-statement:
<ul>

  <li> <object type="text/sitemap">
           <param name="Name" value="Top node">
           <param name="Local" value="top.htm">
       </object>
       <ul>
         <li> <object type="text/sitemap">
              <param name="Name" value="subnode in topnode">
              <param name="Local" value="subnode1.htm">
              </object>
      ...
       </ul>
       
  <li> <object type="text/sitemap">
           <param name="Name" value="Another Top">
           <param name="Local" value="top2.htm">
       </object>
  ...    

</ul>

Index file (.hhk)
Index files have same format as contents file except that ID params are ignored.
