On a Mac there are key combos for many diacritical marks, but since you--like me--are on a Windows machine, the best I have found is to copy paste from Windows's Character Map utility, although I figure there are probably easier ways.

Take a look at PopChar for Windows. https://www.ergonis.com/products/popcharwin/

You can also do it from the text menu (NOT the lyrics menu) with Insert > Symbol...

Thank you both. I'm using the character map accessed from run/charmap and it's working pretty well. I'll check out PopChar later. 

On Windows 11:

Win + '.' (Period)

Go to Symbols Tab (5th from Left, Second from Right).  It looks like various symbol icons in 2x2 grid.

Go to "Latin Symbols" Tab

Select the character you want to insert.  When you click it, it is inserted into the document at current cursor position.

Voilá ;-)

This is the preferred method of doing this since Windows 10 (IIRC).  Won't work on earlier versions of Windows (definitely not Windows 7).  It's faster than accessing them via the Character Map utility.

I use windows 11 and finale 26.  I prefer to use the text option offered in lyrics as I don't need this facility for anything else.  It is only available in click assignment, which is horrible to use for madrigals due to the many melismas and split words.  If I try to type the accented word in click assignment then click it into the correct position this is impossible as the cursor defaults to the beginning of the piece.  Any ideas?

Again, I'd recommend PopChar for Windows.

And complain about the cursor defaulting back to the beginning. I did, years ago. And still waiting for a fix.