I take it you are talking about a combobox from the Forms toolbar, but in Excel rather than Word.
What version of Excel are you using? It makes a big difference.
Later versions do not really encourage the use of controls created by the Forms toolbar. They encourage the use of ActiveX controls from the Controls Toolbox.
Forms toolbar controls get their item lists from cells. This is a huge difference from Word, where you input the dropdown items. Now Help states that you can edit text, but this only works for controls that have a caption, like a check box.
To refer to the Forms control, I think you need to refer to the Shapes collection, but frankly, I thought the Word object model has its oddities, but Excel! Yikes. I find it very strange indeed. I think I will leave this to the Excel gurus. But you are right, there is no FormField collection that I can find in Excel.
Gerry