Hi there,
You could always try this....
http://www.newsoftwares.net/folderlock/

there is a free download and if you like it it is very cheap to buy. (about $30US I think) Not sure but I think the free version works for quite a while anyway (but with a few nag screens or reduced features)

There is loads of info on their website so have a look and see if it is what you need.
best wishes
Tony