try this, obviously you can get rid of the msgboxes if you want to:
You need to set a reference to Microsoft Scripting runtime in the VBA/ tools / references
Sub checkfl()
Dim FSO

Set FSO = CreateObject("Scripting.FileSystemObject")

Dim objFSO As New FileSystemObject

wkbk = ActiveWorkbook.Name


Worksheets("sheet1").Range("b3") = Path
Path = Worksheets("sheet1").Range("b3")


 For i = 3 To 8
       Workbooks(wkbk).Activate
        newname = Worksheets("sheet1").Range(Cells(i, 4), Cells(i, 4))
        
        filepath = Path & newname
        If objFSO.FileExists(filepath) Then
          MsgBox (filepath & " has been found")
          Workbooks.Open Filename:=filepath
        Else
          MsgBox (filepath & " Not found")
        End If
Next i
End Sub
I didn't understand this at all so obviously the code doesn't do it:

The code also needs to move on to the find the next sheet if the current ones are missing from the folder.