Is there a short way to convert a string like

THIS IS A STRING FROM A FORM. I NEED THE FIRST LETTER OF EACH SENTENCE IN UPPERCASE.
to
This is a string from a form. I need the first letter of each sentence in uppercase.

i.e. into sentence case or do I have to come up with an elaborate script?

Things to consider:
  • The letter i when it's on its own needs to be in uppercase.
  • Ideally acronyms need to be in uppercase.
  • If the string includes more than one sentence then each first letter of the sentence needs to be capitalised.