A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
You could use
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
'This macro disables the "Save As" Feature in Excel
'This means that a user will not be able to save this
'workbook(file) under a different name or in a different location
'
'This MUST be placed in "ThisWorkbook" and NOT in a Module.
'
Const strPassword = "secret" ' the password to unlock Save As
If InputBox("Enter the password to display the Save As dialog, or click Cancel") <> strPassword Then
If SaveAsUI = True Then Cancel = True
End If
End Sub
It would be a good idea to password-protect the VBA code too, otherwise anyone can see the password in the code. To do so, select Tools > VBAProject Properties in the Visual Basic Editor, activate the Protection tab, tick the check box "Lock project for viewing", enter the password you want to use in both boxes and click OK. Do not forget this password!
Warning: if the user disables macros, the above code won't run, so the user will be able to use Save As without restrictions.