I am looking for a "Save As" type functionality without changing the
Excel's current file.

What I am trying to do is to save a snapshot of the current worksheet
in CSV format before my macro's logic begins to execute.
ActiveWorkbook.SaveAs method worked exactly like I wanted, but it
changed the current file in the Excel.

SaveCopyAs method would work fine, but it insists on saving the whole
workbook and also doesn't support changing the format to CSV.

I could read the contents of the worksheet, convert to CSV strings,
open a text file, and write to it. But, if there is a built-in
function, I don't want to reinvent the wheel.

Thank you for your time.