How to apply a mask to a String?

Hi I have a credit card number as a String. I need to apply a mask开发者_开发百科 to hide the CC number:

I have "123-123-123" and I need to get something like "123-XXX-123"

Is there any elegant way to do this? I'm trying to avoid using severals substring() functions...

Thanks in advance

myCCStr = myCCStr.replaceFirst("-[0-9]{3}-", "-XXX-");

I believe you can achieve this using PADLeft and PADRight functions of String class.