In order to know how to get women that you really like in the office notice you, start by being friendly. Get her to notice you. Once she did, you could share a joke or two with her during coffee breaks or lunch. Make her see how fun it is to be with you. Most people, not only women, like being around who people who know how to have fun. You can ask her out to buy a dvd and watch it together. You can even volunteer to go grocery shopping with her! It would be nice to know she's already seeing you as a potential housemate.
Another tip on how to get girls like you is by presenting yourself as a boyfriend material. Show those sign of alpha male that is strong and can protect her but has a romantic side at the same time.