Is this possible.

In A1 I have a value 1000, in A2 I have -100 and In A3 +100 (A1 changes and
A2 & A3 create a range around the A1.

I have filtering criteria in A15 a1+a2
I have filtering criteria in A16 <a1+a3

I have table in A20 to L50.

Based on this example, I have to screen column A in the table for values
greater than 900 and less than 1100. I cannot hard code these number because
they change.

I have done a variety of combinations with quotes and equal signs by my syntax
is wrong.

How do I filter column A based on a forumula driven by the variables above?