you would have to set a port/trunk service to auto attendant then you are not in custom dialing menu
I know were you are going with this and the tvs does't not stack/sequence calls very well and if you have a load of lines more then 2 its a resource hog on a little 2 port tva 50. The way I do it ( I haven't done an 824 since 02 ) I use TDA 50g and OGM card disa and you get a true call queue .....and the tva voicemail catches calls with custom dialing menus if necessary...