First of all, I'm sorry for the double post. I didn't know how to reply my own email thread in this mailing list.
I did not see any "reply button" or something like that;
Thank you Rich and Richard for your idea. Yesterday I decided to hard-coded the robot model's name using switch-case.
Which is actually avoid, because I'm simulating a lot number of robots.
case 6666: robot = "robot2"; break;
case 6667: robot = "robot3"; break;
default: robot = "robot1";
sp.SetPose2d( (char *)string(robot).c_str(),x,y, (o- DTOR(90)));
./program -p 6666
playerc error : got NACK from request
playerc error : failed to get response
terminate called after throwing an instance of 'PlayerCc::PlayerError'