Loading Screen Huge Model

Hello i know this question seems to be being asked a lot of times but i searched trough the forums and didn't find something to help me out ...

i want to make a loading screen for my map of a size 1280x1024 and since i read somewhere that the max size is 512x512 is there a possibility that somebody would convert me a loadingscreen.mdx that uses 4 boxes to one that uses enough for a larger pic(6) ??
As i calculatet it would be:

512x512 (TL) + 256x512 (TMID) + 512x512 (TR)

512x512 (BL) + 256x512 (BMID) + 512x512 (BR)

The max is 1024x768. You can over-ride the in-game textures of the melee loading screen (the one with all the creatures attacking eachother, also used for the credits map). The dimensions are as follows:

TL ( 512x512 ) TR ( 512x512 )

BL ( 512x256 ) BR ( 512x256 )

The file types are .blp so it will save map size. Because they are blp, I find they stretch nicely at high resolutions vs .tga.

Thanks