wow...too bad you are not in Sql Server, that's just what it is for....but you can simulate the same kind of thing, i.e. put some place else a little db that has just the info in it that these users are allowed to see, and have them update it all day long. then at like 3:00 am every night update the real data with what they have done. if other people who DO have access to the db are making changes too, tho, it can get messy....again, too bad you dont have SQL server......
good luck-g