VBA EXCEL- copy and paste different documents

Hello, I need ugent help in this task!
The only thing i have to do now is to copy and paste range of texts from one document to another by using MACRO and i will assign it to a button later.
HOWEVER, the copy and paste function seems not working!
It becomes:

Sub Macro2()
'
' Keyboard Shortcut: Ctrl+d
'
Range("A4").Select
ActiveSheet.Paste
End Sub

WITHOUT linking to another document!!

are there any specific scripts that can allow me to do the copy and paste from one document to another?

Thanks!