Regular-expression Required

Hi all,
I am in urgent need for the reg ex that will do the following:
1. Length of string should not be lesser than 10
2. No special characters except ( ) - 
3. Input should not have any alphabet.
for example: this is valid: (123)456-7890
Please  help its urgent, most important - i want to use single RegularExpressionValidator.
Thanks in Advance.
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