Order of Casting

When 2 entirely different spells are based from 1 spell, how can you correct the order of casting the spell. Since the first spell from left to right will always be casted first. Even if you try to cast the 2nd spell, unless the 1st spell is in cooldown, it will cast the 1st spell.

Change the order string. But it`s working only for channel and spellbook.

As kisserz says, you can only either:
1) Base all the abilities on "Channel" and trigger their effects. Change the Order IDs to different things.
2) Base them on different spells.

Even if you change the Order IDs on something different, it has absolutely no effect unless you use Channel.

You can cast the second skill but will require you to remove and replace the first one with a dummy ability, and then order it to cast the 2nd ability, then after casting it, bring the original first ability. But as you can see, its a lot of work compared in using the ability channel which you will just change the base order id. I recommend you to use channel