Netdom Intergration Into Task Sequence for precreated AD computer account

I have a multiple site environment where each of the site admins have rights to the AD users and computers.  I have a working task sequence assigned to unknown computers that we would like to use to allow them to build new machines.  To give them some control, we would like to have the site admins have the ability to create a new computer object in AD and assign that object to computers groups.  These groups would be used to assign the computers to collections to determine what software is installed.  This will allow approximately 50 sites the ability to determine what software is installed on a new machine without having to know anything about SCCM or without needing any assistance from the SCCM admins after the initial group mapping of computer groups to collection is done.  This would allow them to do the leg work first then have the machine boot answer a password prompt and then type the name of the computer that matches the object.  This also prevents us from maintaining hundreds of Task Sequences based on the software that they want installed.  SCCM task sequences do not seem to work properly if the computer name is already in AD.  I am trying to get Netdom to work with a task sequence variable as it survives the reboots and the overwrite of the partition. 
 
Has anyone done this before, and any guidance you have on making this work would be greatly appreciative.  We are trying to give them a "boot it in the afternoon and the machine will be ready for a user in the morning" solution.
 
Thanks

The only thing that comes to mind is to create a webservice to query for the application lists, and then simply use the install software action in the task sequence to install the (dynamic) list.
/ Johan