I'm trying to insert the ":" character in comment field in some specific positions (after the 10th and 15th letter from the beginning and the end of the text). After searching (/t/967/5 the only thing that come is how to insert at the end (appending).
Do you have any idea on how to do that??
PD: It would be nice to learn how to insert a string of characters also at specific positions, or after some characters.
Beside the shown fundamental string manipulations you can choose the fitting string function for your problem out of a set of string functions.
The functions $replace and $regexp are often used too.
See Mp3tag manual "Scripting Functions".