Unfortunately cross project links in CHM files is not something that is easily accomplished. The problem is that the only way CHM files can reference other files is if they know the EXACT FULL FILE PATH where the other CHM file lives which is practically impossible from within another help file.
CHM file topics can be accessed via OS moniker's like this:
mk:@MSITStore:c:\installs\wwhelp\wwhelp.chm::/_03100ware.htm
So you could do:
<<%= HREF("mk:@MSITStore:c:\installs\wwhelp\wwhelp.chm::/_03100ware.htm","Topic Link") %>>
But as you can see the full path is required which is very messy. What you maybe could do would be (assuming the alternate help file lives in the same folder as the current one)
<<%= HREF("mk:@MSITStore:" + oHelp.cProjPath + "OtherHelpFile.chm::/" + lcTopicId + ".htm","Topic Link") %>>
Note that if you do this this will only work inside of a CHM file and Internet Explorer which understands this Windows moniker. If you publish the file to the Web - those will produce broken links.
However, if you use HTML output for your help files (ie. you publish your help file to a Web site) you can easily link the actual link in the help file like this:
http://west-wind.com/wwHelp/docs?page=_03100ware.htm
+++ Rick ---
from Maui, Hawaii