Engraving letters on the Touch Cover

[ml123]

Hi,

How can I engrave other-language letters on the Touch Cover?
I would like to have Hebrew letters on the cover in addition to the English ones.
There is a standard engraving process which will add them to a regular keyboard, but I believe it won't work for this cover.
So, what are my options? Stickers? Writing manually on the cover?

I'm looking of course for an option that won't damage the cover.

Thanks!