In general the comments saying "Alt+Numpad" are correct, however it doesn't work for this character! ♥ is code 3, which is the same as Ctrl+C - typing this at

In general the comments saying "Alt+Numpad" are correct, however it doesn't work for this character! ♥ is code 3, which is the same as Ctrl+C - typing this at the DOS prompt would cancel any input on the current line (and also flush disk buffers IIRC - something left over from CP/M) It is possible to detect if the user pressed Ctrl+C or Alt+3, using BIOS calls or direct hardware access. However, the DOS console driver wouldn't do it this way, and instead convert both into the same ASCII code. The only possible way to pass this character to the "copy" command (which was built into the command interpreter) would be to write a program that invokes "COMMAND.COM /C COPY /♥". Story seems suspicious, if it happened at all it might have displayed "I ♥ SEX" when some other switch was present, then someone mixed things up?