validate hebrew characters??

[HananBa]

I am trying to validate fields in my form that include
hebrew characters.
I define in file validation.xml validation by mask to this
field and give the follwing regular expression :

^[0-9a-zA-Z\-\_\\.\x2d\x5f\/\u05EA-\u05D0]*$

the \u05EA-\u05D0 means hebrew character (I tried the \x...
option as well).

every time I insert hebrew character the validation fails.

any ideas ??