FastCgiServer /home/andreas/MyModule/script/pbweb_fastcgi.pl -processes 3
FastCgiServer /home/andreas/MyModule2/script/pbweb_fastcgi.pl -processes 3
NameVirtualHost *:80
<VirtualHost *:80>
ServerName a.xyz.com
Alias / /home/andreas/mymodulea/script/mymodule_fastcgi.pl/
</virtualhost>
<VirtualHost *:80>
ServerName b.xyz.com
Alias / /home/andreas/mymoduleb/script/mymodule_fastcgi.pl/
</virtualhost>
The end / after mymodule_fastcgi.pl is really important.
