the sysex string you need is this.,
fo,43,10,5b,30,00,13,00,01,f7.
this will turn on insert fx on channel 1.
for the other channels it is.-----
31.32.33.34.35.36.37.38.39.3a.3b.3c.3d.3e.3f.
(channels 2 to 16)
eg,turn on channel 3,is fo,43,10,5b,32,00,13,00, 01,f7.
to turn off, substitute 01 with 00.
hope this helps.
Mick.