I believe you don't want the attack / strenght Xp?
But nope there is no way to get away with that.
The only thing you could do is complete the quest 99% and don't talk to the final guy. This way you can enter the dungeon etc, but you don't gt the xp.
If you really need it completed for other quests or something.. I have no clue if that can be done :/
Depending on the final outcome of everything involving EOC, you might be in luck. Apparently at the moment, your combat level will go by your highest level in Atk/Str/Mage/Range.
I'm guessing you have a higher Strength level? If so, I would just wait to decide next month when the whole update will supposedly happen, because you may be able to get away with it then.
Who knows...either way might not like it, as it seems they are trying to get rid of pures anyway.