Dim q As DAO.QueryDef, p As DAO.Parameter 
  Set q = CurrentDb.QueryDefs("ИмяЗапроса")
  q.Parameters("[Введите начальную дату:]").Value=Cdate(Ваше_значение_параметра)
  q.Execute 
  q.close: set q=Nothing

Dim DBE, DB
Set DBE = CreateObject("DAO.PrivateDBEngine.36")
Set DB = DBE.OpenDatabase("c:\web.mdb", False)

Set DBE = CreateObject("DAO.PrivateDBEngine.36")
DBE.DefaultType =  2       'dbUseJet
DBE.DefaultUser = "Admin"
DBE.DefaultPassword = ""
Set DB_mdb = DBE.OpenDatabase("c:\web.mdb", False)
set q=db_mdb.querydefs("payments_var2")
q.parameters("[input_month:]").value= 9 
q.parameters("[input_year:]").value= 2007 
q.execute
q.close
db_mdb.close
set q=nothing
set db_mdb=nothing
set dbe=nothing