AutoCAD supports the Unicode character-encoding standard. A Unicode font can contain 65,535 characters, with shapes for many languages. All AutoCAD SHX shape fonts are now Unicode fonts.
The text files for some alphabets contain thousands of non-ASCII characters. To accommodate such text, AutoCAD supports a special type of shape definition known as a Big Font file. You can set a style to use both regular and Big Font files. Specify normal fonts using the FontFile property. Specify Big Fonts using the BigFontFile property.
AutoCAD provides ways to substitute one font for another or to specify a default font. For more information see Substitute Fonts.
This example changes the FontFile and BigFontFile properties. You need to replace the path information listed in this example with path and file names appropriate for your system.
Sub Ch4_ChangeFontFiles()
ThisDrawing.ActiveTextStyle.BigFontFile = _
"C:/AutoCAD/Fonts/bigfont.shx"
ThisDrawing.ActiveTextStyle.fontFile = _
"C:/AutoCAD/Fonts/italic.shx"
End Sub