looping shape keys

I have following problem:-
Ive exported an animated model (same one, but duplicated and scaled in Blender, so there is illusion of few SF mushrooms), and it was .MD2, and blender has animation now defined in 240 shape keys (about 10 seconds of animation).

What would i like to achieve is to repeat these in timeline (so when there is shape key no 240, to “jump” back to shape key no 1. )
How I can do that - when i cannot see where are those shapes set in timeline…? I guess it would be too painfull to make shape keys relative and to define each of 240 s.k. influence in timeline! I guess there must be a easier way?
Reason why i do not reduce the number of keys (in fact i have about 10 crucial keys in my animation program, other frames are tweens) is that I would loose correct movement of sceletal animation (armature was converted to shape keys when imported with md2 importer to Blender).

Thanks in advance!