Well now I dont work with NDS but I think that I can help you.
If I remember correctly, the event's coordinates are not for a single map, coordinates are for the whole worldmap.
The (0,0) is located at the northwest. Every map is 32x32 tiles so if you look at the matrix editor in SDSME you will be able to know which coordinates has the map you want to edit the events.
For example if a map in the matrix has the coordinates x:3 y:4, the events on this map will start in x: 3*32 = 96; y: 4*32 = 128.
At the moment I know how to edit the titlescreen in DP with texture coordinates animation. BW and HGSS have textures coordinates animation, texture animation (not texture coordinates) and bone animations.
I was able to edit bone animations in HGSS but the result was weird and I dont recommend it to you. First you should try with titlescreens in DP
Well, sorry for my english and I hope I've helped you. If you have more questions I will try to answer! ;)