you dont need dayz commander, the only you need is to have the arma2+arma OA folder ready
0.-create a folder called daizy or whatever you want.
1.-copy the content of arma 2 and paste in "daizy" new folder you create
2.-copy the content of arma 2 OA and paste in daizy folder and overwrite if ask
3.- go here
http://kodabar-dayz-daizy-single-player-forum.1084782.n5.nabble.com/Unofficial-DaiZy-releases-f1086.html and enter in mod-thread you wanna play and follow the instructions.