Similar to User Defined Fields you can also define your own User Defined Functions. They will also be defined in the Main Window->Participants Data->User Defined Fields/Fcts.

Assume you would like to change the upper/lower case of words, so that the first letter is in upper case and the other letters in lower case. For this you could define a function RightCase:

RightCase(x)
lcase(left([x];1)) & lcase(mid([x]; 2))

You can use the new function like any other function now. For example this will return Raceresult:

RightCase("raCEreSuLt")

Functions can also have several parameters. As an example, define a function add:

add(x;y)
[x]+[y]

The names of the parameters can be defined freely. When using them in the definition of the function, they have to be in square brackets.