Generate a regex from a plain-English description

Build me a regex.

What I want it to match: {{match_description}}
What I do NOT want it to match (counter-examples): {{do_not_match}}
Where I'll use it: {{context}} (e.g. Google Sheets REGEXEXTRACT, JavaScript, Notion 'Find', Zapier filter)
Sample inputs to test against (optional): {{sample_inputs}}

Return:
1. THE REGEX, ready to paste — formatted for {{context}}.
2. PLAIN-ENGLISH walkthrough of what each part does.
3. TEST RESULTS: for each sample input, "matches" or "doesn't match" with one-line reasoning.
4. KNOWN LIMITATIONS: 1–2 edge cases that'll slip through.

Choose the SIMPLEST regex that does the job. Don't over-engineer.