When you roll two combat dice for your viper legion, you rolled one is heroic and one is lore, can i first use heroic to use the ability give enemy unit one poison token, then use lore side to give enemy a damage?

What do the rules say about committing and resolving dice? Your answer will be clear.

I don't have the rules in front of me, but, if committed dice resolve at the same time, then the lore result gets you a token. If committed dice resolve in an order of your choosing, you can trigger the ability and then use the lore result to get the damage.

Most times, I'd rather have the lore token than deal the damage so I can see if my opponent will spend the two lore to get rid of the poison counter.

Thank you, I get now.

The reference book says: "If a unit becomes poisoned during a combat roll, lore results produced during that roll may be commited to cause one damage each." (Reference book, page 7)