Not currently, but it doesn't matter if you have both 10 digit and 11 digit numbers being dialed, you can use separate dialplan entries for them:
exten => _9NXXNXXXXXX,1,AGI(
agi://127.0.0.1:4577/call_log)
exten => _9NXXNXXXXXX,20,Dial(${VICITRUNK1}/${EXTEN:1},,To)
exten => _9NXXNXXXXXX,n,Hangup()
exten => _91NXXNXXXXXX,1,AGI(
agi://127.0.0.1:4577/call_log)
exten => _91NXXNXXXXXX,20,Dial(${VICITRUNK1}/${EXTEN:2},,To)
exten => _91NXXNXXXXXX,n,Hangup()