Can't insert characters with their codes (ALT+code on numeric keypad)

It should be possible to insert characters based on their decimal code number via ALT+code on keypad, on Windows it's working in two ways:

• Inserting legacy MS-DOS characters (via Alt+[code] without leading zero, e.g. Alt+3, Alt+254)
• Inserting Unicode character (via Alt+[code] with leading zero, e.g. Alt+0169)

In the legacy case, the system uses current OEM/DOS code page for inserting characters. If the input character code is greater than 255, it will be truncated to the least significant byte (i.e. code & 0xFF).

References:

• https://www.instructables.com/How-to-insert-symbols-using-alt-key-numpad/
• https://www.freecodecamp.org/news/alt-codes-special-characters-keyboard-symbols-windows-list/

Afaik it's never been implemented.