As I said, I may be wrong, but anyway, I think in your case, what you need is the CCRenderTexture, maybe combined with the spreadsheet. For the CCRenderTexture, I can give you some examples on cocos2d v0.8.2, but I am sure it will be similar. What you do is, instead of creating a Sprite, you create a RenderTexture, be sure you put the right with and height, depending of your orientation as well:
RenderTexture *rt = [RenderTexture renderTextureWithWidth:480 height:320];
[rt begin];
Then you create your set of Sprites, but instead od add to the layer, you just call the visit method:
Sprite *sprite = [Sprite spriteWithFile:@"image_path.png"];
[sprite visit];
Then add the RenderTexture to the layer:
[rt end];
[self addChild:rt z:DEPTH_ORDER_HERE tag:RENDERTEXTURE_TAG_HERE];
And that's it, you only have one combined texture to be called when redrawing.