DHCPv6-PD external script on commit

[Ing. Martin Brázda]

Hello.
I have isc-dhcp server 4.3.4 with my own HACK, that execute external 
script on commit.
Script add leased IPv6 prefix to routing table on router, that is in 
DHCPv6 RELAY role.

Can I do this in current version without hack?
I found "on commit" in manual but without suitable example.
In external script I must have 1. leased IPv6 prefix, 2. mask, 3. client 
IPv6 address and optionaly 4. relay server IPv6 address, 5. interface 
name (or id) on relay server.

Thanks for reply M.Brazda