In wow, you can not cast more than 1 spell on the global cooldown at a time. Both Searing Totem and Lightning Bolt are on the global cooldown. You will never be able to cast both at the same time, even though ST is instant cast.
The next best option would be a cast sequence macro. This allows you to cast a series of spells in a certain order. This mechanic requires you to click the button multiple times. Each successive click advances the position in the list, until it is reset or reaches the end, in which case it starts over.
In wow, you can not cast more than 1 spell on the global cooldown at a time. Both Searing Totem and Lightning Bolt are on the global cooldown. You will never be able to cast both at the same time, even though ST is instant cast.
The next best option would be a cast sequence macro. This allows you to cast a series of spells in a certain order. This mechanic requires you to click the button multiple times. Each successive click advances the position in the list, until it is reset or reaches the end, in which case it starts over.
/castsequence searing totem, lightning bolt
~Elamari