Search url in article content (body)

Hi All

Is it possible and if so, how do I search for a url (to images) in a article?
Years back we imported our articles from another source into Zendesk Guide with all images pointing to a specific server.

Need to move these images elsewhere which means updating the url and trying to determine which articles needs updating (vs opening each one)

Tried eg: api/v2/help_center/articles/search.json?query=downloads.page.com
With and without placing downloads.page.com in double quotes.
And replacing '.' with %2E.

Seems its only searching for 'downloads'
Guess this could work if I then do a find on the results, but first prize is getting only the affected articles.

Thanks