Program flow

START

START statement in column M. When this statement is processed an empty scriptfile is opened and from that moment on all rows containing data other than statements or commentsis interpreted as AutoCAD command syntax and is written into the opened scriptfile.

STOP

STOP statement in column M to close the scriptfile and end the processing of rows. The rows between the START and a STOP buildt up the the main program.

GOTO <row>

GOTO statement in column M forcing processing of rows to continue on the row specified by the <row> argument. You use this to jump out of your main program to a subroutine.
All values in the cells in columns A to K and on the same row as the GOTO statement are copied to the corresponding cells of the row where you jump to.
<row> the actual number of the row which will be processed next. This value needs to be in the cell directly next to the GOTO statement (column N)!

RETURN

RETURN statement in column M forcing processing of rows to continue with the next row directly below the row which stated the last GOTO. You typicly use this to end a subroutine and jump back into the main program.

FOR <> IS <start> TO <end> STEP <step>

FOR repeats (loops) a group of rows a specified number of times.
<> cell used by the FOR statement as a counter. (cool to reference in your calculations!)
<start> this is the inital value of <>
<end> this is the final value of <>
<step> this is the amount <> is changed each time trough the loop.

NEXT

NEXT statement in column M forcing processing of rows to jump back and continue with the row which stated the last FOR. (You can nest FOR NEXT loops 16 times).