It is difficult using the ALT codes if you don't have a keyboard with a number pad (like on a laptop) but if you have a number pad, there all manner of doozies you can use.
Also, if you are running Windows, there is a thing called the "Character Map" (you can search for that on your PC) which has these things to, but there are TONS of things to sift through to find what you need. It shows as a small pop out screen:

You just find what you want, click it, then click select, then copy, then you can paste it wherever you need it