I don't see why not. Just make sure you include the reference in your project to the Microsoft Excel 12.0 (or whatever) Object Library (Tools->References...). Does each team have the same number of players? If so, you could do a loop, something like:
Code:
Dim i as integer
Dim wkbkTarget as Workbook
Set wkbkTarget = Excel.Workbooks.Open(C:\path\filename)
For i = 1 to 10 '//If there are 10 players//
ComboPlayers.Additem wkbkTarget.Range.Cell("A", i)
Next i
I don't know about that exact syntax on the wkbkTarget.Range.Cell part (you might have to reference a specific worksheet) so you'll want to mess around with that probably. If each team doesn't have the same number of players you could always just keep a count in one of the cells on the excel sheet, then just retrieve it and put that into a PlayerCount variable (integer or long) at runtime.
Good luck.