Merge first sheet from multiple workbooks without new sheet every time

[Aandyw42]

I find the merge macro really useful for pulling all the data from sheet 1 in multiple workbooks together onto one sheet in a single sheet workbook. The problem I have is every time it runs it creates a new workbook/sheet when I actually need it to overwrite the old data in the same workbook it created the first time I ran it.

Any help gratefully received