^TI^'
^TITW^history 
^TITW^add 
^TIS^command 
^TITW^exec 
^TI^' Command
^P^
Adds the 
^S^command
 argument to the history list as a new event. If the optional 
^B^exec
 keyword is specified 
then the command is also executed and its result is 
returned. If 
^B^exec
 isn't specified then 
^S^command
 is not executed, and an empty 
string is returned as result.
