charging to and from walls

[The Thing from Beyond the Edge]

This curiosity came up while playing in the new Rise of the Runelords game tonight.

So, if you are not familiar with it and want to play without getting a spoiler you may wish to stop reading here.

Spoiler:

There is a particular room with a goblin on a giant gecko.
I believe the goblin was using ride by attack.
In doing so, the goblin was starting 10 feet high on the wall and out of reach from melee fighters without reach weapons. Then the goblin, on the gecko, would come down and make a ride by charge on a character then go back up to another wall and out of reach.

My question is one of interpretation.
Would the gecko be allowed to come 10 feet down the wall and then along the floor as part of a charge? Could that still be considered "directly toward the designated opponent" if the opponent were 10' (or more) from the wall?
If yes, I don't think there is any more to say. But, if not?
Note: I'm assuming that if there is one 5' square between the all and the character that the gecko and rider coming down the wall would move through that column of squares and be able to make an attack and keep going with ride by attack.

If not, would it need to make a jump from its starting position?
Technically, would one need to draw the profile of combat area to supplement the overhead view and then determine the path it would need to take (fitting a line's path into the given squares) and then make a jump check in order to cover as many spaces through the air as needed?

Edit Note: Perhaps this should have gone in a different forum. I'm not sure where it should go...

[Kazaan]

This is kind of in line with the question, "If I'm standing on a cliff, and my opponent is directly below me, can I make a charge straight down?" This, arguably, automatically satisfies the "directly towards" requirement. But even under Ride-By-Attack, it reiterates that the Charge is a straight line and your continued movement must be along that straight line after you hit the target. So even if you made a "diagonal" charge by jumping, the straight line path of the charge would take you into the ground so you cannot continue your path using ride-by. Now, can you make a normal charge at an angle through the air? It depends on whether through the air is considered difficult terrain. I'd venture as to say "no" since air doesn't really "hamper" your ability to move through it; you can make an acrobatics check to move through open air so I'd say that, if the charger is clinging to a wall and they want to charge a target diagonally through the air, they must declare their charge (spend the action economy) and then make an acrobatics check to see if they can jump that far. If they fail to jump far enough, they fall short and have wasted their full-round action. If they fall prone, they take the prone penalty to attack. In any case, the tactic of charging down a wall, past the target, and up another wall is entirely invalid based on my analysis of the rules.

[The Thing from Beyond the Edge]

Thanks for the response.