Custom string: set bj_lastCreatedLightning = AddLightningEx("<lightning code>",true,x1,y1,z1,x2,y2,z2)
for checking the lightning codes create a GUI lightning creater action
convert it to jass and look from there
they are like "CHLP" (I mean 4 character string)
after than use it with Last Created Lightning Effect when destroying or setting it to a variable
... you got me