search/find by unicode codepoint

I've been trying to use the search/Find and Replace tool to search by Unicode
codepoint. I know I'm using the right syntax/punctuation, because when I
search on ^100, it correctly finds all the 'd' characters. But when I try
searching on a codepoint in a "private use" codepage *, it just doesn't find
anything.

Specifically, there are numerous 0xF020 characters plopped into this
document alongside (badly used) Symbol font versions of ≤ ≥ characters, and
Word displays them sometimes as combining dots underneath these adjacent
characters, and sometimes as little question-mark boxes (ï€*ï€*) beside them.

(Hm, when I paste them in this browser window, they show up as the combining
dots, and mess up the cursor position on the line of text where they sit.)
But either way, when I toggle the Unicode, Word tells me they're 0xF020's,
and that hex translates to 61472 decimal - and a search on that always
returns "Word has finished searching the document. The search item was not
found."

(* Yeah, long story: I get documents from the EMEA - European Medicines
Agency - and some of them have,... strange characters and formatting. I know
these private use characters aren't SUPPOSED to be used, but for some reason
they're there, and I need to be able to programmatically find and replace
them.

Is this just a known loophole, that Word doesn't bother searching on
characters in "private use" or undefined codepages, or is there something
else that it's hiding from me?

To search for (decimal) Unicode, you can use ^u61472 ...

But since you usually don't know the decimal code, it's easier to copy/paste
the character into the Find dialog (Ctrl+C/Ctrl+V), or to type the hex code
into "Find what" (F020) and the toggle it with Ctrl+X (ToggleCharacterCode):
That works in most dialogs, too.

Regards,
Klaus