Ksp reference Manual

20.6. Changing FX from KSP
Introduction
Prior to Kontakt 5.5, there was already the infrastructure in place to get info about the content of
effect slots via engine parameter variables like 
$ENGINE_PAR_EFFECT_TYPE
and built-in con-
stants like 
$EFFECT_TYPE_FILTER
(see Module Status Retrieval).
Starting with Kontakt 5.5, it is also possible to change FX with the same set of built-in variables.
Example
on init
set_engine_par($ENGINE_PAR_EFFECT_TYPE,$EFFECT_TYPE_FILTER,0,0,-1)
set_engine_par($ENGINE_PAR_EFFECT_SUBTYPE, $FILTER_TYPE_LDR_LP4,0,0,-1)
end on
Inserts a 4 pole lowpass ladder filter into the first group slot