Replace 0 with Ø in ham radio call signs using Perl

Since ham radio call signs can contain both the letter O and the digit 0 at the same time, the zeros are often represented as a slashed zero in print. But because there's no ready-hand (Unicode) character for this, the letter Ø is used most often instead, since one cannot always use a monospace font which already represents the zero in slashed form. (This problem could also occur in other cases, such as printing hashes or codes.)

There's a lot of ham radio logging software outside that supports a workflow for printing QSL cards or label stickers, and I'm not sure if any of these supports the replacement of zeros with Ø before print—only in call signs, and not in other data such as date, time or frequency. The software I use on Ubuntu, CQRLOG, exports QSOs into a CSV file that can be read in by gLabels to perform or prepare the actual print. I wanted a step in between that transforms that CSV file by substituting that Ø only in call signs. It took me some time, but here's my solution (showing a bogus CSV line):

I stuffed this regex pattern into this alias:

Update: Fixed the pattern to allow prefixes that start with a digit.