1 - substr : extracts a substring from a string.
syntax: substr (string position length);
string - string to be used
position - integer position from where you want to start extracting the string. (first character position is 1)
length - upto what point youwant to extract string
for eg. if you have a string say str winrunner; and you want to extract a part of that string then you can use.
sMainStr "Winrunner";
sFinalStr substr (sMainStr 4 8);
report_msg ("sFinalStr"); # sFinalStr "runne"

2- load: loads a compiled module into memory
syntax: load(module_name);
You can make your scripts as compiled module (File->Test Properties; Test Type) say you have your code defined as different functions and you want to call these functions from/inside different scripts for this you can make your script(or set of scripts) with all

your code as compiled module and "load" it before calling funcitions.

You can use "unload " at end of your test.

3 - invoke_application : invokes a window application from within a test script
syntax: invoke_application(file command_option working_dir show);
file : full path of application
command_option : command line options to apply (optional)
working_dir : working directory for the specified application
show : how application appears when opened
eg. invoke_application("calc" "" "" SW_SHOW); #opens win calculator application

4- edit_get_list : not sure if this function exist.
For what pupose you want to use this function may be i can suggest any altenate function.

Hope you get some idea on above functions for detailed usage refer WR "TSL Online Reference"

Regards
- AK