I might be wrong..but...
I don't think the script can't handle your name. A list in a script can hold many names and/or UUIDs.
The first thing that comes to my mind, since you have a long name,is: have you checked with your friend (the one who added you to the security) that he/she transmitted your name correctly to the script? Usually scripts want exact informations, a matter of a capital/small letter can bring the script to not recognize you. There are also scripts well compiled, able to recognize avatars even if they result in their list with a capital, instead or small and vice versa , letter.
Although seeying your name I can't notice that you have more then one capital letter, not just Name Surname.
Try to check if they typed the name correctly first, would be even better to select your name with the mouse and do a CTRL+C -> CTRL+V in open chat.
To answer your question.
You can't change your name, and especially for that matter (that might sound pointless to LL), I don't think they would change it for you.
Best Regards,
Oromis.