How to determine the count of Worksheet Tabs that is visible in the Sheet Tab on Excel?

Question

In Excel, how can I determine which worksheet tabs are currently in view across the bottom of the window (Sheet Tab)? i'm looking for a object property to show if this sheet tab is in view or it is under some other object.

Worksheet.Tab object has no related properties. UIAutomationElement has a property called .isOffScreen but it is allways giving false result no matter what the element is visible to user or not.

I tried UIAutomationElement and this is the code example so far.

Sub Test()
    Dim AppObj As UIAutomationClient.IUIAutomationElement
    Dim oInvokePattern As UIAutomationClient.IUIAutomationInvokePattern
    Dim oAutomation As New CUIAutomation ' the UI Automation API\
    Dim oPattern As UIAutomationClient.IUIAutomationLegacyIAccessiblePattern
    Dim ouAutomation As New CUIAutomation
    Set AppObj = WalkEnabledElements("Excel")
    Dim ControlName As UIAutomationClient.IUIAutomationCondition
    Dim ControlType As UIAutomationClient.IUIAutomationCondition
    Set ControlName = ouAutomation.CreatePropertyCondition(UIA_NamePropertyId, "Sayfa7")
    Set ControlType = ouAutomation.CreatePropertyCondition(UIA_ControlTypePropertyId, UIA_TabItemControlTypeId)
    Dim testElement As IUIAutomationCondition
    Set testElement = ouAutomation.CreateAndCondition(ControlName, ControlType)
    Set MyElement = AppObj.FindFirst(TreeScope_Descendants, testElement)
    If MyElement Is Nothing Then Exit Sub
    Dim isOffscreenProperty As Variant
    Debug.Print MyElement.CurrentIsOffscreen
    Debug.Print MyElement.GetCurrentPropertyValue(UIA_IsOffscreenPropertyId)
End Sub

this allways gives me false as a result. i can't figure out if this object is visible (in the view) to user or not.