i've never done it pulling from an xml file, but from a database you can do something like
Code:
Dim conn As ADODB.Connection
Dim rs As ADODB.Recordset
Dim sql As String
set conn = "Driver={SQL SERVER};Server=myServer;Database=myDb;UID=me;PWD=****"
set sql = "SELECT name FROM tableName"
rs.Open(sql, conn, 3, 3)
do until rs.eof
cboCombobox.AddItem(rs!name)
rs.movenext
loop
set rs = nothing
set sql = nothing
set conn = nothing