InTrust script to enumerate laptop or desktop computers by AD Site.

In our AD forest they have put all desktop and laptop computers from all AD sites in the same OU. All the desktop computer names begin with "D" and all the laptop computer names begin with "L".
I would like to be able to build separate InTrust sites for gathering jobs for the laptop and desktop computers by site. 
As an end result would like to have InTrust Sites organized -
   AD Site A Desktops
   AD Site A Laptops
   AD Site B Desktops
   AD Site B Laptops
   ... and so on
I would like to do this by InTrust enumeration script, perhaps filtering the computer names in the OU examining all the ones that begin with D or L and then filtering the results by site from the command "nltest /server:<computername> /dsgetsite".  Unclear how to do this most efficiently/reliably in an InTrust script.  And there might be a more eloquent way.
Thinking perhaps somebody has already travelled this path and can provide tips or even a script.