To acquire the Cactus symbol instead, set your insertion pointer where you need it, then hit 03A8 and Alt+X to receive the Cactus symbol.

Another easy way to get the Cactus Symbol on any PC is to use my favorite method: copy and paste. All you have to do is to copy the symbol from somewhere like a web page, or the character map for windows users, and head over to where you need the symbol (say in Word or Excel), then hit Ctrl+V to paste.