I can use the Glyphs panel to use a character with a manually selected alternate glyph. But how can I programmatically get this glyph id?

I am currently using IDrawingStyle::GetSpecialGlyph , but it only works if the base character has no Unicode representation. But, say, if I reset some alternative character for the character U + 0041 ʟᴀᴛɪɴ ᴄᴀᴘɪᴛᴀʟ ʟᴇᴛᴛᴇʀ ᴀ in the document using the Glyphs panel, the base character will be U + 0041, so IDrawingStyle::GetSpecialGlyph will not work. How can I programmatically get this glyph id?
R. Martinho Fernandes
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