Apple - Can I force Mac OS X to select certain Wifi network?

Sure. Just go to System Preferences/Network, select Wifi and click Advanced. A list with all the Wifi networks you've been connected to will appear. Just rearrange the connection order (the ones you'd like to connect first on top) by drag-dropping.

Also, delete any unwanted network SSID (network names) if you no longer want to auto-join that.

You could also uncheck the "Remember networks this computer has joined", in combination with "Ask to join networks", ensuring that the one you want is in your preferred list.

This will then mean the computer will only connect to the preferred list in order that they appear. If they are not available for any reason it will simply ask you to join another (if it finds one), without then saving that network name in your list and joining it automatically subsequently, meaning you will be asked each time, even if you have used it before.