The simplest way to go to bda is to add in the .cshrc file of
each user an alias like:
alias bda 'cd /"path"/bda ; source .bdarc ;
source .alias.bda'
cd will move you to the basic directory bda, source .bdarc will initialise the environment variables, source .alias.bda, useful aliases.
The .cshrc file should also contain the following instructions:
set lpath = ()
set lcd = ()
set cdpath = (.. ../..)