UserForm events

[spamless]

I'm designing a user form. Here's a screenshot of it.

While I'm happy enough to have gotten this far, I'm stuck now.

Notes:

• The list box has only two choices, dollars or euros. The scroll bar is working. That's all I want there for now.
• I have a separate table with dollar-euro exchange rates by year. It's called "USD.EUR".
  • E.g., for 2021 it says "0.8460" (as per the IRS's suggested annual conversion rate).
• Objects are named as follows:

What I want:

1. The first text box (top-left, UserEntry) should let me enter currency values only.
2. Once I select the currency unit and the year and click "Convert," the lower text box should populate with the converted value.
3. The lower right-hand box should just populate with the opposite currency denomination to the one I selected in the list box.
4. When I click on "Clear," the three textboxes should clear.

I would be grateful for any help!

/dr