rexrainbow - Thanks for your help!
I can't seem to be able to get a plugin call to work, though: It always returns NaN...
//Runtime
Acts.prototype.SetX = function (tilemap, zX)
{
cr.plugins_.Tilemap.prototype.Exps.PositionToTileX.call(tilemap , fake_ret , zX);
this.testing = fake_ret.value;
};
//edittime
AddObjectParam("TileMap", "Set the tilemap");
AddNumberParam("X", "X");
AddAction(6, af_none, "Get tilemap x ", "", "gets test x", "No Description", "SetX");