Have you considered cutting the image up and applying it to limbs?
eg:
`Dummy object you'll attach the skybox limbs to:
make object cube 1,0
`Make a plane for the mesh for the limbs
make object plain 2,100,100
make mesh from object 1,2
delete object 2
`Add the limbs
for t=1 to 5
add limb 1,t,1
next t
`Offset, rotate and texture the limbs accordingly
rotate limb 1,1,0,180,0
offset limb 1,1,100,0,0
texture limb 1,1,SkyBox_North_Image
.
.
.
rotate limb 1,5,90,0,0
offset limb 1,5,0,100,0
texture limb 1,1,SkyBox_Top_Image
`Done!
This is only pseudo-code but you get the idea, if I were to make a skybox, this is the way I do it.
Hope this helps,
Broken_Code