Help: having some trouble dublicating a character

Let's suppose that Zapf Dingbats \x6b is what we want.
This is how I'd do it:

1. Create a Character Format named "Dingbats".
   Set all fields of the dialog to As-Is or blank except:
   Family: ZapfDingbats
2. Special > Variable [Create Variable]
   Name: char.symbol.asterisk-full
   Definition: <Dingbats>\x6b<Default ¶ Font>
3. Anywhere you need this:
   Special > Variable
   {select char.symbol.asterisk-full from list}
   [Insert]

You might need to play with the point size in the Chr Fmt.

Yes, you can hand type this as a local override, using some special keyboard sequence.

Doing it as a variable has numerous advantages: It avoids having the next character be a Dingbat too, if not also the wrong size. You don't need to memorize or look up the key sequence, font name, etc. every time you need it. You get global control over all instances, in case you find a glyph you like better in some other typeface. If used in a heading, it will appear as an "*" instead of a "k". Spell check won't hassle you about the "k".