Because there are a nearly infinite number of combinations. Generic instructions are available in the User's Guide, section 2.3 . CAD GETs fail, and when I look at dyncadget.out or try one manually, I get the source code of specweb99-cgi.pl. Your web server is not set up correctly to execute .pl scripts. Check your web server documentation.
Some web servers require the Content-type to be set for POSTs.
There appears to be a bug in Netscape Enterprise Server where it does not pass the POST data to stdin of the Perl cgi script correctly. CAD GETs fail on Apache with error 500. Chances are that upfgen99 or cadgen99 did not run correctly to generate User. Personality and Custom. In your document root do you have files called User.