Comment by nneonneo

Unicode has support for this, in the Ideographic Description Characters block (https://en.m.wikipedia.org/wiki/Ideographic_Description_Char...). However, it’s purely descriptive, and not designed for rendering.

There are somewhat more sophisticated systems which define both the rendering and stroke decomposition of characters (e.g. CDL: http://guide.wenlininstitute.org/wenlin4.3/Character_Descrip...). The general workaround for characters that aren’t on Unicode would be to use one of these stroke description systems to create the character, then render it to an image and insert it.