Need RTS unit selection help

I have been following the the RTS tutorual videos for…ndrLDG__OAZs7Q

but the rest of the video is more geared towards Tropico style RTS city builder, I have so far gotten building placement and edge scroll and mouse control working along with the ghost build and cannot build working…

I am wondering if anyone who has followed the above tutorial videos have done a simple building / unit selection move code they would be able to share?