MATLAB: Howto replace Element with Element from another Vector at the 1st Element’s Position

MATLABposition;replace elementsvaluevectors

Let's say I have a Vector with 100 integer Element between 1 & 100 in no particular Order.
A = [1:100];
A = (randperm (length(A)));
my 2nd Vector can be of any length and contains Integer Elements of any size. Let's Make it:
B = randi([1 200],1,250);
e.g. 250 Elements between 1 & 200 in no particular Order.
Elements of a Size beyond the Dimensions of Vector A don't interest me, so
B (B > 100) = NaN;
Here's what I wanna do:
To Replace all Integer Values in Vector B with the Value in Vector A at that Number's Position.
So let's say the First Element of B is 45. I want to replace it with the 45th Element in Vector A.
If the 2nd Element in B is 89, I want it replaced with the 89th Element in Vector A.
The NaNs just stay NaNs.

Best Answer

B =
30 100 NaN 20 NaN