Need help on Dial String for Pap2 for home use please....

Is there someone other than Linksys that perhaps can answer a question related to this article on dial strings for the PAP2??
Linksys PAP2 Dial Plan Tutorial


Below is an example string:

(<:1780>[2-4]xxxxxxS0|*xx|<911:17804213333>S0|011[2-9]x.|1[2-9]xx[2-9]xxxxxx|1900xxxxxxx!)

Wanted to know how to change string so that if a 704 is dialed as an area code (US North Carolina), then a 1 is prefixed to the number so that the number dialed is 1704xxxxxxx?

Or if this cannot be done, then a 10 digit number is dialed I need the string to add a 1 in front of it making it an 11 digit number.

Most of the numbers stored on my phones for the 704 area code do not have a 1 prefixing them. But using my VOIP provider, it needs a one. The rest of my numbers outside of 8704 area code have a one stored in the phones...

Thanks,
Peter