in reply to Adding content blocks to a static website
Second (and third, fourth....) moritz' recommendation. Some so-called experts -- those with more concern for being "in style" with a fad than with functionality -- frown at server side includes as "obsolete" or "outdated." But SSI seems to me to be an optimal answer to your question.
OTOH, I'm not sure I understand your situation. There seems to be a contradiction in your description:
"I have to add several news items to a static website. ...I have nothing to do with the website..."