Digging up an old topic here...but felt compelled to give a voice ^^
viewtopic.php?f=38&t=218
^^ This brings you to the @JJ@ Mod clientside, the only "public" clientside that lets you use cg_thirdpersonrange.
You can technically use this on other servers, but I would not advise doing so, mainly because this clientside alters the scoreboard by showing your Kill / Death rather than just the score.
Using this on other servers will basically break the scoreboard on your screen as everyone's score will read 0/0 even though it's not.
If you have some C experience, you could get a copy of the 1.04 MP code and make your own client to enable cg_thirdpersonrange. It's not very hard if you use a nice piece of software like Visual Studio or something similar.