If you are using one of the fonts that allow it, holding down the ALT key while typing 0146 will add a +/- to the text string. The list of texts that have the "extended characters" is in the manual.
If you're using a TTF font you can see what's available (and the ASCII number) you can use Windows' built-in Character Map (in Win10 it's under Windows Accessories); if you're using an SHX font download the Character Map AEC file from DC LLC (https://www.datacad.com/ddn/fonts_ref.html - links to PDF and AEC files are under "DataCAD Standard Font Chart") and change the font to the one you want to use. If it's not shown it's not available.
Highest Regards,
Alan T. Hendry, RA Intel i7-12700F (2.10 GHz) Desktop, 16GB RAM, 1TB SSD, Win 11 Home 64-bit, DC 23 w/ latest beta Intel i7-10750H (2.6GHz) Laptop, 16GB RAM, 1.5TB HD, Win 11 Home 64-Bit, w/ DC 22, 23 & latest beta