Starting on the Regency Hotel (Sports R/A) go straight on R/A untill the next traffic light (Ahmed Bin Ali St), keep going straight until you reach the civil defense R/A (you will see the firetrucks here and only one building on your front left corner), here make a left (Al Istiqlal St) and keep going until you reach the Arch R/A, keep going straight(now you are in Lusail St), until you reach the Doha Exhibition Center (A red/beige building on your right hand side, and the Intercon Hotel right behind it), reach the R/A and make a left taking Onaiza St, from here you can follow previous details and you might get to it wthout any problems.

Hope this one is more detailed...best regards!!!