Before getting to the question, a comment: \d is probably not matching what you expect... it does indeed match [0-9], but also matches a whole lot more, and that could cause problems later.

Building a vanilla regex to match 50 - 250 is quite wordy. (Starts with a 5, 6, 7, 8 or 9 plus one more digit, or starts with a 1 with two more digits, or starts with a two followed by 0, 1, 2, 3, or 4 plus one more digit, or exactly 250)

The simplest way might be to capture up to three digits, and then do a next unless ($3 > 50 && $3 < 250) after you've found a candidate.