Change case of first letter using regular expression

[Lila]

Hello all,
I have a question about the replace options in regular expressions.
I need to search for the first letters of my paragraphs in my curriculum (built over a long time) that are in lower case and move them to upper case.
I put in search

^[:lower:]

and it works just fine. Unfortunately the only way I found in order to change it to appear upper case was to replace the found adding the “upper case” as effect. Unfortunately this is not actually changing the case, infact it will still find it next time I search for it and simply disapper nex time I remove direct format. Is there a way to actually replace the character case like in other programs? I thought something on the line (Sublime Text) in replace:

\U$0

Any hope this is already working with a different code or to add this feature? maybe with alternative search and replace (I could not manage to find the beginning lowercase string for it XD)?
Thank you for your time reading and sorry if my menu commands sound strange, but I use libre office in italian.

[Lila]

Fast update:
I found how to do this with the Alternate Search and Replace extension (I owe them a LOT!)
With Uppercase/lowercase ticked, find:

^[a-z]

replace

\U&

[mikekaganski]

Use your regular expression to find all. Then (when all occurrences are selected) use Format-Text-UPPERCASE.

[Lila]

Thank you, Mike, but unfortunately Format–>text–>uppercase only change the appeareance, at least in 4.4.5
edit: sorry, I did not read your answer properly. Unfortunately replacing all of them in one go was not the option, but again thank you!

[mikekaganski]

In 4.4.5 (quite old version!) the relevant menu item is Format-Change Case-UPPERCASE.

I suppose that you misunderstood me as if I meant character formatting dialog. Actually I meant menu item that does actual case replacement.

[Lila]

Yes, sorry for the confusion. Your answer works perfectly if you can change all initials to uperrcase. Unfortunately I had some emails and bullet list items I did not wanted to make uppercase, but lukily I found how to it with alternate search and replace! I should update but some of my script are no longer working on >5

[mikekaganski]

I’d advise to try to fix scripts. You may ask for help here on ask forum, if it makes troubles. New versions come not only with new (and possibly useless of course) features, but also with bug fixes.

[mikekaganski]

Also, please make your answer the accepted one, not mine. And close the question, too, to indicate for others that it is solved with accepted solution.

[Lila]

Sorry for the late answer. I cannot accept my own answer (not enough points). But I will try to close the question!