If WB1 is your main wb and WB2 is your hidden  wb, and
WS2 is the sheet  in WB2 containing the data of interest,
then maybe something like this will help..

Dim aaTEMP as Variant
aaTEMP = WS2.Range("A1:A400")
b = b

assuming you want to copy  col A (natch, change as req'd).
Then, put a break at "b = b", and examine the contents
of the array aaTEMP in your locals window. If it has
successfully been populated, then you can just "dump"
it's contents into WB1.