Inserting Unicode characters in filenames

I have filenames that need characters that are forbidden in windows so I use Unicode characters that look almost the same. I can't figure out a way to type these directly (such as A729 for the colon). Instead, I just copy them. Oddly, if I assign a key to the necessary sequence using PowerToys, it works. Can anyone give me guidance here?

The standard method of inputting them via the keyboard in Windows requires a keyboard with a numeric keypad:

You can also find and input a lot of symbols in the "emoji keyboard" (which isn't just emoji) you get by pushing Win+. and clicking on its symbols tab.

Thanks, I'll figure out what works on my machine. Also, copying from OneNote works, which is what I have been doing.