I am sorry for asking this but I was under the impression that this only works with munitions. Recently, I encountered someone who used quickdraw's target lock for soontir fel to reroll his primary weapon.

When a friendly ship at Range 1-2 is attacking a ship you have locked, the friendly ship treats the "Attack (target lock): header as "Attack:." If a game effect instructs that ship to spend a target lock, it may spend your target lock instead.

That's how it works AFAICT but it's still controversial. For 3 points it had better give an extra action...

The person you encountered was absolutely right.

Please read the FAQ.
The entry you will be looking for is here:
Q: What are examples of game effects that instruct a player
to spend a target lock?
A: The cost for a secondary weapon such as Proton Torpedoes, using pilot
abilities like Lieutenant Colzet, or spending a target lock during the "Modify Attack Dice" step to reroll attack dice are all examples of spending a target lock. Removing a target lock or assigning a blue target lock token to
another ship are not examples of spending a target lock.

And if you need further confirmation one of the Developers (Max Brook) confirmed it on a Goldsquadron podcast

Double post

The break down of the card is this.

When a friendly ship at Range 1-2 is attacking a ship you have locked,... If a game effect instructs that ship to spend a target lock, it may spend your target lock instead.

The trigger for the 2nd sentence is a game effect that spends a TL and the reference to that ship is the friendly ship at range 1-2 attacking a ship that you have locked. It has no need of the remainder of the first sentence since the second sentence doesn't have the tag "If you do..." which would require the previous effect to happen.

Thanks - so it works on colzet too - that is nasty

Nope. I thought so too. But Colzet triggers after combat while TS is during combat.

Or rather: TS triggers when a friendly ship is attacking

It works on Colzet in that it allows him to use QD's lock for rerolls and keep his for his ability - but Colzet almost certainly wants FCS anyway, so it's kind of immaterial.