|One word of caution. Once you complete the above action you cannot remove the original column with the phone numbers or else you will lose the "new" numbers in the concatenated colum.|
You can "break" the link between the cells so you don't have to keep the original by doing the following. 1) Select the colum with the new concatenated value, fromt he menu select Edit<Copy, 3) From the menu select Edit<Paste Special, 4) In the dialog box that comes up select the option "Value" in the top half and select OK.
The values int he new column will now include the area code but will no contain the formula from before and you can delete teh original phone number column.