need both module and CGI version of PHP (debian)

I have a web server (debian 2.2) that already runs Apache and PHP4 module version. Everything has been configured using debian packages and works fine. Now I also need the CGI version of PHP because I want to use it on the command line and in a selfmade program that is only able to use CGI. I can't find any PHP sources installed on the system and webmin won't let me install php-cgi as there is already the "php" package installed. How do I install or reconfigure PHP so that I have both versions? I'm afraid of completely reinstalling PHP by hand as it is necessary to work correctly for the web server. What should I do? Thanks, Udo