Does a player need to decide to spend the lock before measuring for the coordinate or jam?

Or can the player for example, say he is coordinating then measure to a ship that is just outside range 2 and then decide to spend the lock to ignore range restrictions?

Came up in a game yesterday where I had a ship on the border of range 2 I wanted to coordinate too, and the next round my Upsilon was going to be well beyond range 2 but wanted to keep my lock for that round to coordinate.

You're fine measuring first.

BHCC says "while you coordinate or jam." The steps to performing a Coordinate action are as follows:

Quote

1. Measure range from the coordinating ship to any friendly ships.

2. Choose another friendly ship at range 1–2.

3. The chosen ship performs one action.

You would use BHCC during step 2, after you have measured.

EDIT - as a note, this would work the exact same way for Jam, as the mechanics are identical (save that you must choose an enemy ship at range 1).