PURPOSE: To directly start a simplified language program from system environment other than a desk top environment for the simplified language program, in which the processing of an operation in the desk top environment is programmed by providing a command analyzing means and a start control means.

CONSTITUTION: When the simplified language program existent in the desk top environment is started from the other system environment, first of all, a command interpreting means 16 interprets a start command sentence instructing the start of the simplified language program and instructs the start of the program. Next, a start control means 17 searches the simplified language program to be started in the desk top environment while receiving the start instruction. Thus, concerning the simplified language program in which the processing of the operation in the desk top environment is programmed, this simplified language program can be directly started from the other system environment.