Flash MX 2004 (7) - Sloping Isometric Tiles

Hi

I'm using Tony Pa's still Excellent tile base Tuts (http://www.tonypa.pri.ee/tbw/) for part of a Isometric tile based game with mouse clicking movement. Now, all that went fine, as expected, but i'm having trouble trying to add slopes, as to give the effect of going 'Up' to a raised hill area.

Now, i have designed the tiles, go up one layer, and the slope itself (going from bottom right to top left basiclly).

The basic path finding code is all square based so you walk from one tile, to the one next door to it. This is creating the first problem with slopes, as you basiclly need to start on one square, move diagonally across the tile next to it, to move to the tile above. and doing the same but backwards to move down, shouldn't be hard once the first creation is done but that, right now, is also a problem.

Here is a quick image of the point in question. Yes, it's temporary graphics which is why Popuri from Harvest Moon 64 ^_^