l2tp tunnel authentication

We have Cisco working as LNS to accept connections from LAC

Part of cofiguration is:

vpdn-group 2
accept-dialin
protocol l2tp
virtual-template 1
terminate-from hostname tunelcisco
source-ip xxx.xxx.xx.x
l2tp tunnel password 0 cisco

We wish to change this Router with Mikrotik, and we need to keep
l2tp tunnel password 0 cisco
in configuration ( l2tp tunnel authentication ).

We are curently unable to set Mikrotik for This.
Have Anyone some idea for this.

Client use dial-in access to LAC which is configured to use l2tp tunel with authentificatin and forward trafic to LNS which then consult radius.
Any Help ?