One light for object shadow and another light for ground shadow i want to have a toon effect on the objects and for the ground shadow i need a different lighting angle, otherwise i have too long shadows... i work for this in cycles render mode.

have one SUN at the moment, and it casts a hard shadow on the objects.
how do i get the second SUN to just cast the ground shadow on the ground plate?

thanks in advance
This is doable with layers and render layers as cegaton suggests.  Here is one way to set it up.

Put all your objects (except ground and lamps) on layer A.
Put the ground on layer B.
Put the "object shadow lamp" on layer C.
Put the "ground shadow lamp" on layer D.

Set up your render layers as follows:
Render layer one (objects and object shadows): include layer A (objects) and layer C (object shadow lamp).  Exclude layers B and D.

Render layer two (ground and ground shadows): include layer B (ground) and layer D (ground shadow lamp).  Exclude layer C.  (Do not exclude the objects on layer A, you still want them to cast shadows.)

Don't forget to check "Transparent" under the Film tab in the render settings.  You can handle your background/environment in another render layer, with no objects and an Environment pass.

Then composite the two layers with an "Alpha over" node.

Objects and object shadows:



Ground and ground shadows:



Composite:



Composite with environment: