If I understand you correctly, here is how you can get the URL to the privacy tab (assuming that you want to be on the homepage of the portal):
Dim ctlTab As New DotNetNuke.Entities.Tabs.TabController
Dim portalStgs As DotNetNuke.Entities.Portals.PortalSettings = DotNetNuke.Entities.Portals.PortalController.GetCurrentPortalSettings
Dim tabInfo As New DotNetNuke.Entities.Tabs.TabInfo
tabInfo = ctlTab.GetTab(portalStgs.HomeTabId, portalStgs.PortalId, True)
Dim strUrl As String = System.Text.RegularExpressions.Regex.Replace(tabInfo.FullUrl, "(Default\.aspx)", "ctl/Privacy/Default.aspx")
Please note that in the example above, you can remove the namespaces in most modules. Also, the PortalSettings are typically already available through the ModuleBase Class. I only included them here for context.
Here is how you would do that same thing in a typical module:
Dim ctlTab As New TabController
Dim tabInfo As New Entities.Tabs.TabInfo
tabInfo = ctlTab.GetTab(Me.PortalSettings.HomeTabId, Me.PortalSettings.PortalId, True)
Dim strUrl As String = System.Text.RegularExpressions.Regex.Replace(tabInfo.FullUrl, "(Default\.aspx)", "ctl/Privacy/Default.aspx")
Here is how you do it for the current tab:
Dim strUrl As String = System.Text.RegularExpressions.Regex.Replace(Me.PortalSettings.ActiveTab.FullUrl, "(Default\.aspx)", "ctl/Privacy/Default.aspx")