Here are the special characters which are used in different languages. I found them online years ago, and they have been very useful. Among them are the characters that are used in Portuguese. They can be easily typed on Windows using a set of codes. Below are the codes and the instructions of how how to use them.
Turn on the Num Lock option on your computer keyboard. On most keyboards, you turn on Num Lock by holding down the Shift key and pressing the Num Lock key. There may be an indicator light on your keyboard that shows whether the Num Lock option is turned on.
While holding down the Alt key, type the number of the character you wish to enter from the following table. Then, release the Alt key.