Depending on what version of APPX you are using and how you are accessing it, you may be able to hold down ALT, use the numeric keypad to type the ascii code value in decimal, and release ALT, to enter that ASCII char.

Or you can do it with ILF code;

 SET OWN WF ASCII CODE = 176
 CNV BIN OWN WF ALPHA 1

 ... where WF ALPHA 1 is painted on the report or screen. The other variable
 is a three-digit numeric field.