If you have a Regular Expression that you think should work, try entering the pattern into the first box and then a sample into the second and press the button to see, although in this one you don't need to have a / at the start or end of the pattern :

Regular Expression Sample Test
Check Entire Text
Case Insensitive

Replace With :
Checking the 'Check Entire Text' box adds a /g to the Regular Expression and ticking the 'Case Insensitive' adds a /i

You can refer back to this page at any later date and try out any Regular Expressions that you are putting together.