Good news: nLite can probably do the job, with an add-on CAB
Bad news: It's a DIY project all the way. No one can legally post such an add-on here.
Collect Service Packs & hotfixes: The most reliable way is to install a plain vanilla MS Office, connect to the OfficeUpdate site, and follow the info links to their parent KB article. Download full-file or IT Pro versions wherever you're given the option. Extract the .MST file (you won't need any others). You could also retrieve the patches from WINDOWS\SoftwareDistribution\Download, after a completed update.
Perform administrative install, and slipstream your updates:http://unattended.ms...xp/view/web/45/
The list of hotfixes is out of date, but the process and commands are easily adaptable.
Download and install ORKtools:http://download.micr...US/orktools.exe
Use Custom Installation Wizard to create your unattended answer file (.MST). Bonus points if you saved your personal settings (.OPS) with the Profile Wizard, to have ready for integration at this point.
Office Shrinker: usable on a limited set of language versions. Production machine cannot have had Office previously installed--clean Windows install or VPC are best.http://www.msfn.org/...showtopic=16709
Repack Office and unattended configurations into 7-zip (or RAR) switchless installer.http://www.msfn.org/...showtopic=39048
Create integrated Add-On, and include Office in same step of nLite as your Windows hotfixes.http://www.msfn.org/...showtopic=63596
Things can go wrong at most steps of the process. It may save time to test your creation at various points along the way. Good luck with your project. I'm just about to test final product with mine.