Updating custom combobox by changing value on worksheet

[tiredofit]

I have a custom combobox created in my workbook on the ribbon.

This is the xml code:

<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"> 
  <ribbon startFromScratch="False"> 
    <tabs> 
      <tab id="CustomTab" label="My Tab"> 
        <group id="Group1" label="MyGroup"> 
          <comboBox id="MyCombo" 
                    label="Attributes" 
                    sizeString="AAAAAAAAAAAAAAAAAA" 
                    onChange="ComboBox_OnChange"> 
            <item id="First" label="Apples" /> 
            <item id="Second" label="Oranges" /> 
            <item id="Third" label="Pears" /> 
          </comboBox>  
        </group> 
      </tab> 
    </tabs> 
  </ribbon> 
</customUI>

This is my VBA code:

'Callback for MyCombo onChange
Sub ComboBox_OnChange(control As IRibbonControl, text As String)

    Cells(1, 1) = text
    
End Sub

If I make a change to the combobox, say I choose "Apples", cell A1 on the worksheet changes to "Apples". If I change the value in the combobox to "Pears", cell A1 changes to "Pears". This is what I want.

In addition though, I want to occur, ie if I change the value in cell A1 from "Apples" to "Oranges", I want the combobox to update with the value "Oranges".

How can this be done?

I tried all sorts of Invalidating the combobox but for some reason, it doesn't update.

Thanks

 

[tiredofit]

EDIT SORTED:

<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"
onLoad="Initialise"> 
  <ribbon startFromScratch="false"> 
    <tabs> 
      <tab id="CustomTab" label="MyTab"> 
        <group id="Group1" label="MyGroup"> 
          <comboBox id="abc" 
                    label="Attributes" 
                    sizeString="AAAAAAAAAAAAAAAAAA" 
                    onChange="ComboBox_OnChange" 
                        getText="Module1.Combo_GetText">
            <item id="First" label="Apples" /> 
            <item id="Second" label="Oranges" /> 
            <item id="Third" label="Pears" /> 
          </comboBox>  
        </group> 
      </tab> 
    </tabs> 
  </ribbon> 
</customUI>

Ths was omitted:

onLoad="Initialise">