Regex To Split Text Doc Into Chapters Starting on ODD Page Break (right facing side)

[Nin]

Hi everyone!
I'm looking for input, and I hope you can help me.
I must split a lengthy document into chapters, and every chapter must start on an odd page break.
The author wrote as one long text, flowing from frame to frame.  They started the new chapter at the top of the page as 'CHAPTER xx.'

Here is the regex code I wrote to Find And Replace in Affinity Publisher.

Find:  CHA(?=PTER)   Replace:  <Odd Page Break symbol>CHA      NOTE: it is not case sensitive.  Manual.  I must select the correct 'chapter' from the found list and click replace.

I'm having a difficult time creating a pattern code where the replace knows to add the odd page break at the space in front of the word Chapter.  
Note:  sometimes the author used complete uppercase, sometimes it is the first letter uppercase.  

How would you approach this problem?
I'm on macOS Monterey Version 12.3.1 and using Publisher 1.10.4.

Any and all input is greatly appreciated!
 

Edited April 25, 2022 by Nin
Add in my systems I use.

[walt.farrell]

I'm not sure I understand the variants you're dealing with. All the hearings you showed just use CHAPTER.

Things might be simpler if you restrict the hits to items that start a paragraph, e.g.,

Find ^CHAPTER

[Nin]

2 hours ago, walt.farrell said:

I'm not sure I understand the variants you're dealing with. All the hearings you showed just use CHAPTER.

Things might be simpler if you restrict the hits to items that start a paragraph, e.g.,

Find ^CHAPTER

Oh, I feel very silly.  That never occurred to me.  Thanks Walt!

[walt.farrell]

You're welcome.

If it's still not good enough, let us know what further problems you have and someone can probably help.