If you use deltayaw and deltapitch (assuming you don't really need to know the roll) then there is no need to have the separate pivot. The following should work.
where target is your target entity
turnentity missile, deltapitch(missile,target)/25,deltayaw(missile,target)/25,0
I understand that the two (undocumented) delta commands return values from -180 to 180.
where target is your target entity
turnentity missile, deltapitch(missile,target)/25,deltayaw(missile,target)/25,0
I understand that the two (undocumented) delta commands return values from -180 to 180.