I read over your post again and noticed that you said that it wasn't a data-entry form, but was used to lookup and the edit data. In that case, I've attached a database by which you can model your own. Or you can recreate your own form based on the idea.
1) Create a form (will be a subform later) and have all of the fields you'd like on it (Part ID Number and Location).
2) Create another form that will be used as your main form.
3) Add a textbox to the main form. Change the property of autotab to yes. Set the input mask at the length of the parts id (assuming they have a standard length. If they don't, this solution won't work).
4) Add a subform to the main form, choose the subform you created earlier.
5) Add some lookup razzle-dazzle in the after_update event of the textbox on your main form.
Code:
Private Sub txtLookup_AfterUpdate()
Dim db As DAO.Database
Dim rs As DAO.Recordset
Dim check As String
check = "SELECT * FROM tblEbay WHERE PartIDNumber=" & Me.txtLookup.Value & ";"
Set db = CurrentDb
Set rs = db.OpenRecordset(check)
If Not rs.EOF Then
Me![subEbay].Form.RecordSource = check
Else
MsgBox "No record found."
End If
End Sub
6) Profit.
I've attached the database so you can have something to play with.
EbayLookup.zip