The character functions are all very nicely organized in the Scripting Index. When you need to manipulate a string, you can very easily go through the various functions and the examples shown, to determine which one to use.......You need to spend the time to do this!
For what you are trying to do....
Names Default to Here( 1 );
dt = Current Data Table();
For Each Row(
:Substring = Substr(:Substring, 5);