Making VBA Word add-in change the default RibbonUI tab - vba

Question

(Be kind to me; I'm not a professional developer!)
I've created a custom Word ribbon with all sorts of business-specific functionality. I think it's awesome, but there are some old-school people here who want the built-in "Home" tab to show up by default because that's what they're "used to."
I added a menu option to change the default between the Home Tab and the HMF tab. The problem is that I can't actually figure out how to use the setting to change the active tab.
Here's a snippet of the ribbon code:
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" onLoad="HMFRibbon.InitializeRibbon">
<ribbon>
<tabs>
<tab id="HMFTab" label="HMF" insertAfterQ="TabHome">
[...]
</tab>
</tabs>
</ribbon>
</customUI>
My STARTUP folder contains an "HMF_Toolbar.dotm" that includes the following code in the "HMFRibbon" module:
Public ribRibbon As IRibbonUI
Sub InitializeRibbon(ribbon As IRibbonUI)
On Error GoTo DefaultError
If GetSetting("HMFToolbar", "Defaults", "HMFIsDefault") = "False" Then
MsgBox ("Leaving 'Home' as default tab")
Else
Set ribRibbon = ribbon
MsgBox ("Activating 'HMFTab'")
ribRibbon.ActivateTab ("HMFTab")
End If
Exit Sub
DefaultError:
MsgBox ("Could not find default toolbar setting.")
End Sub
The code runs the first time a document is open, finds the right default and shows the right message, but doesn't actually change the starting tab to HMFTab. It also only runs when the ribbon is first opened, so even if it worked the first time it wouldn't run when subsequent documents were open (would would again default to "Home").
I tried moving the function to "AutoOpen()" in the HMFRibbon module, but that only fires if I open "HMFRibbon.dotm," not another document with the module loaded.
So... any ideas?
EDIT: I should have been clearer. By "default tab," what I really mean is that I want the ribbon to automatically activate either the "Home" or "HMF" tab depending on whether HMFIsDefault is true or false.
I've gotten closer by using the Application.AutoOpen function, but it fires before the ribbon is actually loaded, so "active doesn't work! Here's the code:
Option Explicit
Public WithEvents oApp As Word.Application
Private Sub oApp_DocumentOpen(ByVal Doc As Document)
On Error GoTo DefaultError
If GetSetting("HMFToolbar", "Defaults", "HMFIsDefault") = "False" Then
MsgBox ("Leaving 'Home' as default tab")
Else
MsgBox ("Activating 'HMFTab'")
HMFRibbon.ribRibbon.ActivateTab ("HMFTab")
End If
Exit Sub
DefaultError:
MsgBox ("Could not find default toolbar setting.")
End Sub

Answer 1

The IRibbonUI.ActivateTab method can be used for activating ribbon tabs. You just need to pass the Id of the custom Ribbon tab to be activated. You may also find the IRibbonUI.ActivateTabMso method for built controls and IRibbonUI.ActivateTabQ which uses the fully qualified name of the tab, which includes the ID and the namespace of the tab.
You may consider using the insertAfterMso attribute for the custom ribbon tab if you want to place it after a specific built-in ribbon tab.
Compare the following attributes:
insertAfterMso - Specifies the identifier for the built-in control after which to position this control.
insertAfterQ - Specifies the identifier of a qualified control (that is, a control whose idQ property was specified) after which to position this control.
Read more about the Fluent UI (aka Ribbon UI) in the following series of articles:
Customizing the 2007 Office Fluent Ribbon for Developers (Part 1 of 3)
Customizing the 2007 Office Fluent Ribbon for Developers (Part 2 of 3)
Customizing the 2007 Office Fluent Ribbon for Developers (Part 3 of 3)