Fromindex returns all arguments joined by a string after a certain argument in a command.
This variable has one optional argument after the integer which can be the default response should there not be any arguments after the defined argument in a command.
For example, you could have the command
$(fromindex2 No index 2!) and could try
!fromindextest No-args after-2 and you will get a response of
No index 2!, else the command will return an error
command arguments here