VBA Copy a range of cells values using the range of cells in a formula (which will change)

I want to be able to extract the range from a sum formula and then copy that range to a new column
Given that this cell range will constantly change,

Formula in cells are:
Cell A1 Sum(A1:A28)
Cell A2 Sum(A2:A29)
Cell A3 Sum(A3:A30)
ETC....

Sub aa()
Dim x As Long
Dim y As Long
Dim z As Long
z = minimum cell in range in A:A select cell
x = Select the first number from formula in active cell
y = Select the second number from formula in active cell
Range("A" & x & ":A" & y).Copy Range("b1")
End Sub

The above text in bold is what im looking for

Any help is greatly appreciated.

Example

=sum(A2:A101)


Copy cell range A2:A101 To Cell B2

Or

=sum(A20:A1010)

Copy cell range A2:A101 To Cell B2