Adding External Application Buttons to Custom UI Ribbon Bar in Word 365

Question

I'm currently working on customising my UI ribbon bar in Word 365, and I'm wondering if there's a way to add external application buttons, specifically Acrobat Add-in buttons, to my custom tab.

The goal is to consolidate all my frequently used buttons into one tab for seamless accessibility. Since Acrobat provides useful buttons within its Add-in, I'm curious if there's a method to "call" or integrate these buttons into my XML code for the custom UI ribbon.

I revised Adobe forums, VBA forums, Word forums, YT videos and nobody mentions this at all. I have seen this on a MS 2007 custom tab and I believe it should be possible to replicate for 365. Picture attached of what I am expecting to reproduce (this is extracted from MS 2007 or older) Custom UI ribbon tab with Acrobat buttons in DD - MS 2007

Has anyone successfully achieved this or has insights into how it can be done? Your guidance on this matter would be highly appreciated!

This is what I am trying right now but still not working. Tried 'button' instead of 'control' didn't work either. Not sure how to include this buttons into the 'PDF group'

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" 
            xmlns:x1="PDFMarker.OfficeAddin"
            onLoad="RibbonControl.Onload">
                
  <ribbon>
    <tabs>
     <tab id="CustomTab1" insertBeforeMso="HelpTab" label="Toolbar" > 
         
       <group id="CustGrp1" label="PDF">
            <button idMso="FileSaveAsPdfOrXps" size="normal" />
            <button idMso="FileEmailAsPdfEmailAttachment" size="normal" />
  
            <control idQ="x1:ACROBAT_ACTIONS_BUTTON" visible="true"/>
            <control idQ="x1:ACROBAT_ImportComments" visible="true"/>
            <control idQ="x1:ACROBAT_EmailPDF" visible="true"/>
            <control idQ="x1:ACROBAT_Embed_Media" visible="true"/>
    </group>
      <group id="CustGrp2" label="Headings" >
            <button id="Btn1" label="H1" 
                    onAction="RibbonControl.MyBtnMacro" />
            <button id="Btn2" label="H2" 
                    onAction="RibbonControl.MyBtnMacro" />
            <button id="Btn3" label="H3" 
                    onAction="RibbonControl.MyBtnMacro" />
            <button id="Btn4" label="H4" 
                    onAction="RibbonControl.MyBtnMacro" />
            <button id="Btn5" label="H5" 
                    onAction="RibbonControl.MyBtnMacro" />
    </group>
     </tab>
    </tabs>
  </ribbon>
</customUI>