you can add in a new font in the style.css of your theme using the font-face rule.
find a font that has the character that you want to use in it, download it and copy the .ttf/font file into your theme folder, then in the style.css file insert the @font-face rule:
@font-face {
font-family: name_it_what_you_want;
src: url(the_name_of_your_ttf_file);
}
create a style rule in your style.css file to handle this font on the character you want to change:
/* sets the font for a specific character or set of characters */
.funky_character
{
font-family: name_it_what_you_want;
}
then, in the post or page you want to use it in use the text editor rather than the visual editor and create a span element around the character
<span class="funky_character">C</span>haracter
and you should be in the game.