Define a key to execute a DML expression when the key is passed at any INPUT.

 Define_key keyname [/Gold] dml_expression
 keynameAny terminator key that is valid for the %ACTION internal variable.
 The given DML expression is interpreted when the key is entered at any INPUT, MENU, PAUSE, or TABLE_EDIT input.

 Define_key F20 "Spawn"
 ! spawn a subprocess when F20 is hit
 Define_key F20 /Gold "Idml " & var
 ! perform the idml program name that is
 ! contained in 'var' when the Gold F20 key
 ! is hit.