There's no way to do it in version 2.
In version 3, you can match on the internalID variable. Each player will have an Internal ID, which is, as the name implies, an internal identifier that the software uses to uniquely identify every player. You can see this by editing the player on the Database tab, or by editing a player on the Players tab and then pressing the "Edit" button on the Name line. Either of these will bring up the Player Details dialog. The last line should be Internal ID. If it doesn't display, check the box Show all fields. Internal IDs look like this: 9f2481b0-9b5b-11da-1d7b-726563178260
You'll need to specify conditions like this:
internalID = "9f2481b0-9b5b-11da-1d7b-726563178260"
The quotes (") around the ID are important. It won't work without them.