Dim wb As Workbook
Set wb = Application.Workbooks("Book2.xlsx")
wb.Activate
wb.Sheets("Sheet1").Range("A1").Select
Ps: Some times above code working properly ,most of times throwing exception
Looking at this link Run Time Error '1004': Select method of Range Class failed using ThisWorkbook i did the same as above still failing
try to fist activate the sheet and then use the select but first of all do you really need the select? It's the most expensive method you can call (still sometimes needed)
If you just need to read/write a value into the cell you can do it this way