How is this done? What am I missing?
I have a font, it doesn't have this character built in. I need to put one in. Please help!
It's just a regular space -- copy from there. Its encoding as character U+00A0 makes it 'special' -- and only if the software it is used with does use this for what's it been assigned a code point to.
Fairly modern software, such as Adobe InDesign, doesn't really need a hardwired fixed space, it can emulate its behavior.
Does your font license allow modification?
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