Instead of trying to pass the delete sql use the control's .Delete
method and apply a filter for the delete criteria.
VB Code:
  1. Private Sub Command1_Click()
  2.     Adodc1.Recordset.Filter = "Investor_Number = '" & txtInvestorNumber & "'"
  3.     Adodc1.Recordset.Delete adAffectGroup
  4.     Adodc1.Recordset.UpdateBatch adAffectGroup
  5.     Adodc1.Recordset.Filter = adFilterNone
  6. End Sub