Keyboard has limited number of keys and thus it is not possible to accommodate all the special symbols and characters in the keyboard. However, you can find almost every special symbol in Microsoft Excel Sheet and use it wherever needed
You will find the option for symbols in Insert, when you click on this option. It consists of large number of symbols like alpha, beta, Pi etc. To insert any of the desired symbols in your worksheet, just select the symbol and click on Insert.
The option for the Special Characters lies inside the Symbol when you click the Insert Tab on the top ribbon. Here you can get numerous special characters like Registered, Copyright etc. To insert any special character in your Excel Worksheet, just select the desired character and click Insert.