need help with csh

I'm trying to fix up initlocation to accept an environment variable as
an input parameter (in addition to the absolute path name it already
accepts).

I'd like to be able to say:

  setenv PGDATA2 /home/postgres/data
  initlocation PGDATA2

However, initlocation sets a local variable PGALTDIR to the input
argument as the program starts, and I'm fumbling around trying to
evaluate the contents of PGALTDIR as an environment variable.

(So, I need PGALTDIR -> PGDATA2 -> /home/postgres/data, and to assign
the path name back to a local variable.)

Anyone know how to do this? Please??

TIA

                   - Tom