How to find all "I" on end of lines and break it to the next line

Dear People who are more experienced than me,

I checked the forum (also google is my friend) and there were kinda similar questions but I haven't seen any solution for my situation.

The situation:

– I am working on a book.

– Many of the sentences start with "I".

– Sometimes the "I" in the begining of a sentence is also happens to be the last word of a line.

For example:

--

This is very good. I
believe I was here before.

--

– The customer doesn't want the sentence starting "I"s to be on the end of the lines.

The handling I need:

Using our example sentence I have three ways to handle this:

It's either

This is very good.

I believe I was here before.

or

This is very good. I believe

I was here before.

or

This is very good. I be-
lieve I was here before.

So it's: break it to the next line or bring the next word after "I".

Maybe I am not the first one who needs a solution for that. I hope some of you know a solution for this.

Thanks,

gergo

PS: Sometimes I work on Hungarian books and they start sentences with "A" very often. So if you could tell me a solution which can be applied to any chosen capital letter it would be even better.