KornShell scripts can not be directly executed from a shortcut or the Toolkit Scheduler. You have to specify the KornShell as the program to execute and the pass the script to it as an argument.
Example for a Shortcut:
sh.exe c:/fullpath/script.ksh
Example for the Scheduler:
Program: sh.exe
Arguments: c:/fullpath/script.ksh
Notice that the shell requires forward slashes in the path to the script. | 
