GLOBAL_XL.Sheet1 seems incorrect to me. Sheet1 is not a member of the application object. Nor is worksheets a member of the application object
application > workbook > worksheets > name or index #
Set GLOBAL_WS = GLOBAL_XB.Sheet1 maybe...
However, I still think that's an incorrect reference to the specific sheet.
If it's always #1, you could use the index number (can't recall if that is 0 or 1), or WS = WB.Worksheets ("the name")
I was thinking at first the problem was trying to use the name property instead of the caption property, but for now I'm going with what seems to be the fact that your object hierarchy is incorrect.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.