Cannot find the correct Regex solution

I have content that looks like this:

001 B OR 06K24b 01 TCP SC C 02
001 B CC 12K48b 99 BCP SC A 02 1982-11-09
001 B OR 06K24b 01 TCP SC C 02

I want my regex expression to match line 2 but not line 1 or 3.

I think what I need is a positive lookbehind but I’m unsure. Even if I’m correct, I can’t figure out how to correctly apply it.

I have tried the following:

^(?<=([0-9]{3} [A-Z] [A-Z]{2} ..K..b [0-9]{2} [A-Z]{3} [A-Z]{2} [A-Z] [0-9]{2})).*

and Positive Lookahead:

^(?!([0-9]{3} [A-Z] [A-Z]{2} ..K..b [0-9]{2} [A-Z]{3} [A-Z]{2} [A-Z] [0-9]{2}))$

Please guide me to the correct solution. Thanks!