Hi,
You can use the global sliders (view/sliders menu) or the gmem/grecall functions.
For the global sliders, you can use the value of a slider in any other formula by using the slider(id) function. For the global memory, you set a value by calling gmem(id, value) and then you use this value by calling grecall(id).
If you want to reuse your value inside one grid only, then use the mem/recall functions instead of gmem/grecall.