You can sort of do it but it's convoluted. I know you can do boolprop dormspecificcheatsdisabled false and then changelotzoning residential to add items or move things around but I just checked and the inventory is still disabled that way. What you would have to do is go into the lot in build mode, use the cheat changelotzoning dorm (I am using dorm as opposed to residential because you shouldn't need to cheat your sim tons of money to move in there). Have your sim move out and into the 'dorm' community lot. Place the item, save, go to neighborhood mode, have your sim move out and back into their old place (you can use Inge's shrub to keep the furniture from being sold) and then go into the community lot, do changelotzoning community and then save and exit.
You can also do changelotzoning residential to the lot instead of dorm to do this whole process, but then you will have to motherlode your sim a boatload of money to be able to afford the lot and then I guess find some way to get rid of it if you don't want to cheat. I know Monique's computer let's you 'donate' money and Carrigon's tin can bank will take funds out of the household. You can also use SimPE to change the family funds back to what it was.
Heh, where there's a will there's a way, but if you really want to do it, you'll have to jump through hoops.
*edit: Alternately, I noticed Windkeeper over at TSR extracted the rose boquet mesh and made it into a decorative item. It's actually on free rotation right now, but just for today (Saturday).
http://www.thesimsresource.com/items/comments.php?ID=34387&type=ts2objectsOf course it won't have the card, but it will otherwise pretty much look the same.