The CTCP version reply (on IRC networks) is actually hardcoded in Pidgin. Luckily the source is available, and i say "Use the Source Luke!", and bring you another one-liner :)
The change is obvious,... Just change the text between the "\001"'s (I have no idea what they do), and you'll get your own personal CTCP version reply.
The patch works with pidgin-2.5.8