Simple csh question

[Antony Stace <antony@example.com>]

Hi Folks

Simple question....How do I add another directory to an environment
variable with the csh shell.  Ie in bash/ksh I do

PATH=$PATH:<directory I want to add>

ie

PATH=$PATH:/usr/local/mynewprogram/bin

I have tried  

setenv PATH $PATH:<directory I want to add>

and a few other things....but all ways get an error.

Cheers

Antony