Asterisk voicemail.C modification

i wants to make some changes in asterisk voice mail system, so i modified the source code in app_voicemail.c, now i need to create a special DTMF input to browse the old messages folder, i found the follwoing function that used for changing folder:

[code]case ‘2’: /* Change folders */
if (useadsi)
adsi_folders(chan, 0, “Change to folder…”);
cmd = get_folder2(chan, “vm-changeto”, 0);
if (cmd == ‘#’) {
cmd = 0;
} else if (cmd > 0) {
cmd = cmd - ‘0’;
res = close_mailbox(&vms, vmu);
if (res == ERROR_LOCK_PATH)
goto out;
res = open_mailbox(&vms, vmu, cmd);
if (res == ERROR_LOCK_PATH)
goto out;
play_folder = cmd;
cmd = 0;
}
if (useadsi)
adsi_status2(chan, &vms);

		if (!cmd)
cmd = vm_play_folder_name(chan, vms.vmbox);

vms.starting = 1;[/code]

how can i modify it to press 2 for old message directly

I think you need to use the developer mailing list or IRC channel.