It is not possible to connect with a LOGO via any custom Socket communication to the robot (Dashboard Server).
Therefore it is not possible to start or load different programs in that way.
As already mentioned before you could create a switch case in the Main program waiting for Job numbers.
The robot will run thru the switch cases and comparing any GP modbus register to the cases.
Each case is one program.
It has still got one limitation. You are not able to change to different installations.
You might take a look at the brief documentation and LOGO project how to use a LOGO in combination with UR.