Passing unique value to PAM

Need suggestions for the following problem:

On host A I have a serialnumber.  I am launching a remote execution on 
host B.  There is a pam module on host B that needs that serialnumber to 
properly configure the environment for the remote execution, and this 
configuration needs to be done as UID=0.

I've tried the following:

1. Pass serialnumber via TERM - problem: TERM not yet available to 
module via pam_getenv().

2. Run a program to hand-off the data.  This involves forking a child 
from pam module, but env variable is set to so that parent and child 
will have a known rendesvouz on a local socket.  The child waits on the 
socket (it is UID=0).  The parent continues through sshd processing, 
runs a program that then talks to the child on the known local socket to 
send the serialnumber it was provided via its command line from the ssh 
client on host A.

The child uses that serialnumber to figure out how to configure the 
environment and then sets UID to the proper user & forks/execs the 
desired program.

Problem: the child running the desired program skips out  of ssh 
processing.  Seems like a bad thing.

...

So, is there any way to communicate a unique value from the ssh client 
host to the PAM module being executed by the sshd server?  The 
serialnumber is unique to the remote execution I am trying to launch.

Thanks

--
Sam Watters
SGI
watters@sgi.com