Vista - what properties in cs.ini can be called as functions?

Id like to assign funtions called from userexit scripts to the properties in
the CS.ini and Bootstrap.ini but Im not sure which ones can be called as
funtions (i.e. Computername=#function()$)

Id like to write a custom front end that allows the imaging technician to
enter his credentials, the domain name and OU to image the machine and poll a
database with the serial number to return an asset tag as the Computername
property.

can the UserID, UserPWD and computername be assuigned as variables or
functions in this manner? and if so do both the cs.ini and bootstrap.ini have
to be the same?