DIAdem doesn't have a method to open .chm files because these files are Microsoft help files, rather than DIAdem specific help files. However, there is a KnowledgeBase on Microsoft's web page that may be of help. You can find this document at
http://support.microsoft.com/?kbid=209843. I found this by doing a web search for "Programmatically open .chm". I hope this helps you.
Regards,
Shannon R.
Applications Engineer
National Instruments