Let's say you are flying an infiltrator and have Dooku crew and target lock. Can I roll, see what I get, spend target lock, use Dooku to declare a result, then reroll for spending the lock?

Thx

In game terminology, rolling dice is not the same as rerolling dice. To that end, you must declare that you're using Dooku before the dice are initially rolled (rerolls, like target locks, predator, etc. don't count).