I don't know in what way your application needs differ from mine in
detail. In my case, the bulk of the work is done by my MFC application.
Once the data are "inside" of OpenOffice the feedback to the MFC app is
not very complex and essentially only a couple of database entries need
to get written to or updated. I can do this quite comfortably with OO
Basic, which also handles some special menus.
Depending on how your application and OO are coupled, this might not be
a workable way.
One more thing; if your application is part of your job it could make
sense to buy the necessary expertise. Either to get started with UNO
C++, which also would yield a base of working code, or to help with the
project, too (I'd say, once you are comfortable with the UNO specific
things, this should hardly be necessary). It's just a matter of what is
more expensive, because you potentially need to spend more time working
out the details when you are on your own. I am sure that there are
enough experts out there, who are able to offer professional help.