I want to convert a list of existing numbers to the (xxx) xxx-xxxx format.

Using Number->Special->Phone number->OK I am able to have new entries appear in that format, but I can't convert the existing numbers.

Strangely, I was able to convert a test group at home on my Home and Student version, and I assumed the office at my new job would have a pro version that would also work.

I also tried adding a new column to copy/ paste etc.back and forth but the pasted result retains the older format of xxxxxxxxxx.

Any solutions? Thanks.