put this in the ThisWorkbook code module
[vba]
Option Explicit
'
Private Sub Workbook_Open()
'
Call HideSheets
'
End Sub
'
Private Sub HideSheets()
'
Dim Sheet As Object '< Includes worksheets and chartsheets
'
Sheets("Sheet1").Visible = xlSheetVisible
'
For Each Sheet In Sheets
'change name to suit
If Not Sheet.Name = "Sheet1" Then
Sheet.Visible = xlSheetVeryHidden
End If
Next
'
End Sub

[/vba]
Put this in a standard module (call it from the Macro dialog box)
[vba]
Option Explicit

Sub UnhideSheet()
'
Dim ThisSheet As String
'
ThisSheet = ActiveSheet.Name
If Application.Dialogs(xlDialogWorkbookUnhide).Show = True Then
Sheets(ThisSheet).Visible = xlVeryHidden
End If
'
End Sub
[/vba]