Hi, Pawel -
In addition to Andreas' suggestion, there may be another way.
If the font that is being used contains the needed character(s), you can type them (but only if you know the super-secret handshake). Use of the Windows Character Map utility is very helpful. As you'll soon see, it is not a user-friendly process.
For example, if Tahoma is being used, Character Map shows that a superscript 2 character maps to a Unicode value of 0x00B2:
In the lower-right corner, you see the decimal equivalent of 0x00B2 (0178). If you hold down the Alt key and type 0178 on the numeric keypad, Windows will translate this keypress sequence into the Unicode character 0x00B2.
Example: a²+b²=c²
is keyed as follows: a,Alt+0178,+,b,Alt+0178,=,c,Alt+0178
If this is data that will be contained in a column and ultimately stored in a database, then there may be additional considerations. For example, in SQL Server, strings using single-byte/character encoding are defined using the varchar data type, but Unicode strings use the nvarchar data type. The code page used by the database may also affect character encoding. I call these additional points to your attention in case you are not aware of them.
HTH. Best regards, John
Andreas.