I try to exponentially decrease a value (force) over specific 10 to 11 range.
In other words, if a length of a vector d is 10 cm then force needs to be 1000 Newton. If length d is close to 11 cm then force should be close to 0.
My exponential decreasing formula is doing it, but on a large scale, and i have no idea how to bring it within 10-11 range.
Any help is appreciated!
Here is a demo in excel with the formula unrolled:
Cell M16 = 1000
Cell L17 = 10.1

You want to find the exponential function: $$f(d)=Ae^{rd},$$ where $r$ is the rate of decay and $A$ is a parameter.
Now plug the two points: $(d,f)=(10,1000)$ and $(11,0)$ to make up a system of equations for $d$ and $A$. Once you find the function, you can use it in Excel.