I was gob-smacked to discover that the current version (1.6.2) of the LDAP plug-in for Directory Access supports variable substitution in its LDAP mappings! This wasn't the case with the plug-in not so long ago, so I don't know exactly when that was updated, but I'm guessing only an update ago or so.
We've been plotting a roll out of OS X with Active Directory (AD) authenticaion and roaming/network home folders (on an XServe) for all users but were having problems finding AD attributes to borrow for the three essential User attributes, viz UID, HomeDirectory and NFSHomeDirectory. Now, though UID is solvable one way or another, the two Home Directory attributes were causing some problems. Either we extended the company's global MS AD schema, or borrowed some unused attributes. No longer! We can static map them with Variable Substitution! For example:
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040607084920314