This article refers to current excel versions.
If you have excel 2000 or before you will have to use another method.
One way is to open Word, which in 2000 if not before does have the insert,
Then copy it to excel, where it can be pasted.
for a check mark (tick in the UK) in word it is on the windings font as are
several sort of dots.
for putting in symbols directly by using the codes.