THERE IS an answer for this. U need to modify the DigiMap.
OBI should do this as default - r u listening Obi
HOWEVER, it won't work if u dialed a local 7 digit # then extra VRU digits - if u always use the AC then it will work on local numbers. If u want to require dialing AC all the time take <1919>[2-9]xxxxxx| out of the Map.
this is the default DigiMap
(*xx|1xxxxxxxxxx|<1919>[2-9]xxxxxx|<1>[2-9]xxxxxxxxx|011xx.|xx.|(Mipd)|[^*]@@.)
919 = my AC
Change it to this on the web under advanced - if u chg it on the device Obi will chg it back.
(*xx|1xxxxxxxxxxS0|<1919>[2-9]xxxxxx|<1>[2-9]xxxxxxxxxS0|011xx.|xx.|(Mipd)|[^*]@@.)
the S0 causes the Obi to dial immediately on either of those 2 scenarios so the server will never see the extra digits. If u add S0 to the one that auto dials your local area code <1919>[2-9]xxxxxx it will never let u dial the 3rd scenario <1>[2-9]xxxxxxxxxS0 - so don't do it.
as a note u can require digits to be entered to dial an outside line or a password.
(*xx|<9988:>1xxxxxxxxxxSO|<9988:1919>[2-9]xxxxxx|<<9988:1>[2-9]xxxxxxxxxSO|011xx.|xx.|(Mipd)|[^*]@@.)
9988 then is the password -- careful -- the pw must not match any other possible dial sequence like 011xx