When you transfer a toon, if the name is in use on the target realm then you will be prompted to change your name.
So if you want a name change, then create a toon on the target realm with your name if one does not already exist with that name.
Once you've finished customizing the toon, and click the confirmation box that the changes are good...
You get to type in the new name.
Anything you type here that includes ascii lettering, such as (Alt 130 = é) or (Alt 131 = â) will be rejected.
The process actually brings up another window, where you have to enter a different name.
However, this new window does allow for ascii characters... but it has to be a different name than you picked in the previous step.
Once you enter the name, you will enter the world.
Your unit frame will show the new (second) name entered, but you'll have your first name above your toon.
Once you log out of the game, thereafter both your unit frame and toon name will be the second name you selected.
If you're set on the name Çüéîîâ (Alt 128, Alt 129, Alt 130, Alt 140, Alt 140, and Alt 131).
You know it will be rejected.
So pick anything you want that is not your desired name, but that does include the ascii lettering that will be rejected.
Then when it prompts you for a different name, go nuts on the ascii stuff.