I list two methods to embed a custom shape into a note. What won't work is assigning this via a parameter. Parameters are literal and are not parsed to see if there is any further expansion possible. If this function is required you'll need to hire a developer to create a toolkit application that will do a custom interpretation of your files. This function will probably need to be re-compiled, and possibly re-written, for each new release of Creo and installed for each user.
1) You can create a custom font source, then compile it, and then change the text to use that font for that one character. Commercial installs include the information and the tools to do this. Check the Guides/help for Fonts. The number of users that have done this is tiny. Usually it's limited to adding marks to tell "1" from "I" in the font named FONT.
I see that of late, Creo 3, PTC allows the choice of symbol_font via config option, but I expect they don't let the user select any but the two applicable fonts.
This won't work because the parameter can't hold the alternate font name for the embedded characters.
You can also use "&sym(symbolname)" in the note, where "symbolname" is the name of a symbol already added to the drawing, though it doesn't need to remain displayed.
This won't work with a parameter because the contents of parameters aren't evaluated, just taken as written and displayed.
