Setting DISPLAY variable on a remote XServer session

I have a CentOS system running an X2go server and I use a client machine to connect to it. I'm trying to do some command-line automation for mouse-clicks using xdotool. The automation is scripted in bash and is placed in /etc/profile.d. The idea is when any user logs into X2go server from a client, the automation script should execute. However, there is one issue with this approach. For xdotool, a Xserver session is needed. On further digging, I found that there is no display variable set when the session initiates and therefore the script fails (xdotool). It takes about 30 seconds for the XSession to fully establish before a display variable is set. I cannot simply add a sleep in the bash script at it delays the login process since the script resides in /etc/profile.d. Any neat way to tacke this?