ComboBox in a sheet, not in a UserForm?

Hello All:

I am trying to create a dropdown ComboBox in Sheet2 of my spreadsheet.
I want it to list only column A from a table called SPD2 which has a range
of Sheet1 A2:I31 and then I wanted the value selected from that ComboBox to
be inputed into Cell A10 on Sheet2. I was able to do this by entering a ComboBox
in a UserForm, specifying the RowSource in the properties to be the range from my table,
and then by using the following:

Worksheets("Sheet2").Range("A10") = UserForm1.ComboBox1.Value

I can't get this to work outside of the UserForm, please help. Am I overlooking something?