As a starting point, you could probably use a function like this:
Function file_exists(file_name As String)
Dim fs, fil, fol
Set fs = CreateObject("Scripting.filesystemobject")
Set fol = fs.getfolder(ThisWorkbook.Path)
Do
For Each fil In fol.Files
If fil.Name = file_name Then Exit Do
Next
file_exists = True
Loop
If Not file_exists = True Then file_exists = False
End Function
to check if the workbook exists.
Then something along the lines of:
if file_exists("Workbook Name") = false then
'hide data
else
'show data
end if
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