Algorithm to pick elements in one array that sum to a setpoint, and corresponding elements in other array to average to a setpoint?
In general, no; this problem is NP-hard.  Even matching just the sum (without getting into anything about the average) is NP-hard, as it is the subset sum problem.  Thus, you should not expect any efficient algorithm for your problem that works for all possible inputs.

I notice that in your examples, the numbers are all small.  For that special case, there are reasonably efficient algorithms using dynamic programming: see, e.g., https://en.wikipedia.org/wiki/Subset_sum_problem#Pseudo-polynomial_time_dynamic_programming_solution.

The dynamic programming algorithm in that link describes how to make the sum match, but you can adapt it to make both the sum and average match.  In particular, you have an array $Q[t_1,t_2,i,k]$, which you will fill in with True if there exists a subset of $k$ out of the first $i$ rows whose first column sums to $t_1$ and whose second column sums to $t_2$.  You can use dynamic programming to fill in this array (in order of increasing $i$) in $O(N^4M^2)$ time, where $N$ counts the number of rows in your spreadsheet and $M$ is the largest number in the spreadsheet.  Then, once you've filled in this array, there will be a selection that sums to $s$ and averages to $a$ if and only if there is some $k$ such that $Q[s,ak,N,k]$ is True.

I recommend implementing this in a programming language (e.g., VBA, not Excel).  Implementing it in Excel might be possible but it sounds painful.  See https://cs.stackexchange.com/tags/dynamic-programming/info for our reference material on dynamic programming; if you're not familiar with that subject, you might want to read a textbook introduction to it.