Ask for "Tapcon" screws either at your hardware store or at your homecenter.
With only having to do four screws, your regular electric drill and a cheapo bit for drilling in masonry will work just fine. As you found out, a titanium wood bit is good for...wood. As others have mentioned, a hammer-drill would be best, but I've drilled too mant to recall using a regular old drill. you may have to bear down a bit (no pun intended) to get the hole started.
When drilling in cement, drill in a bit (no pun intended), then pull the bit out of the hole to release the accumulated grit. Repeat until you get to your desired depth.
The box of Tapcon's will tell you what size masonry bit to use. Use the correct size. Smaller and you'll have a heckuva time friving the screw. Too large and the screw may strip the hole. If you buy a larger sized box, they include a bit in with the screws.
Tapcon screws are by far the best screw for tapping, and more importantly, holding, in masonry. My opinion, obviously.