I would like to make sure all phone numbers are updated to conform to this format:

(xxx) xxx-xxxx

I tried to write a workflow rule to address this as follows:

NOT (
   REGEX( HomePhone , "([0-9]{3})[0-9]{3}-[0-9]{3}")
)

However, I get the following syntax error: "Error: Function REGEX may not be used in this type of formula"
Is there a way to use REGEX here?  Is there a better way to go about this?

I

I would like to make sure all phone numbers are updated to conform to this format:

(xxx) xxx-xxxx

I tried to write a workflow rule to address this as follows:

NOT (
   REGEX( HomePhone , "([0-9]{3})[0-9]{3}-[0-9]{3}")
)

However, I get the following syntax error: "Error: Function REGEX may not be used in this type of formula"
Is there a way to use REGEX here?  Is there a better way to go about this?

I