Set MyRec = SubFormControl.Form.Recordset.Clone 

Public Sub NewHist(varCtrID As Long)

Dim stDocName As String
On Error Resume Next
Dim I As Integer
stDocName = "HistoryCtrBOARD_New"

If SysCmd(acSysCmdGetObjectState, acForm, stDocName) >  0  Then
 ' поиск уже открытого документа 
  For Each Frm In colFormsInfoCtr
    I = I +  1 
    'Debug.print Frm.Caption & ": " & Frm.PactID 
    If (Frm.CtrID <> varCtrID) Then
    Else
        DoCmd.SelectObject colFormsInfoCtr.Item(Frm.hwnd & "")
        Frm.Visible = True
        Frm.SetFocus
        Exit Sub
    End If
  Next Frm

End If
  
  Set Frm = New Form_HistoryCtrBOARD_New

  mintI = mintI +  1 
  colFormsInfoCtr.Add Item:=Frm, Key:=Frm.hwnd & ""
   'DoCmd.MoveSize (mintI + 1) * 80, (mintI + 1) * 350 
  
  DoCmd.SelectObject colFormsInfoCtr.Item(Frm.hwnd & "")
   'DoCmd.MoveSize (mintI + 1) * 80, (mintI + 1) * 350 
  DoCmd.OpenForm stDocName, , , , , acHidden
  Frm.CtrID = varCtrID
  Frm!CtrID1 = varCtrID
  Frm.Caption = "Info : " & Frm.CtrID.Column( 1 )
  Call HistoryCtrEventsFormRefresh(Frm, varCtrID, False, False, False, False)
   'Frm.Requery 
  Frm.Visible = True
End Sub

Public Sub HistoryCtrEventsFormRefresh(pFrm As Form, pCtrID As Long, OpShowBills As Boolean, OpShowOfftake As Boolean, OpShowProj As Boolean, OpShowCurr As Boolean)
On Error GoTo Err_Sub
Set conn = New ADODB.Connection
conn.Provider = "MSDataShape"
conn.ConnectionString = "DATA PROVIDER=SQLOLEDB.1;SERVER=EDURSS\SQL_URSS;APP=Microsoft Access;DATABASE=TB2K;Trusted_Connection=Yes"
Set rst = New ADODB.Recordset
rst.CursorLocation = adUseServer
conn.Open
 '@OpShowBills bit,   @OpShowOfftake bit, @OpShowProj int 
  rst.Open "EXEC HistoryCtrEventsP " & pCtrID & _
    ", " & CStr(Abs(OpShowBills)) & _
    ", " & CStr(Abs(OpShowOfftake)) & _
    ", " & CStr(Abs(OpShowProj)) & _
    ", " & CStr(Abs(OpShowCurr)), conn, adOpenDynamic, adLockOptimistic,  1 
  
  Set pFrm.HistoryCtrEventsF.Form.Recordset = rst
  
  Exit_Sub:
   DoCmd.Hourglass False
   DoCmd.SetWarnings True
    Exit Sub
  
Err_Sub:
    MsgBox Err.Number & " " & Err.Description
    Resume Exit_Sub
End Sub

Option Compare Database
Option Explicit
Public conn As ADODB.Connection
Public rst As ADODB.Recordset

.Form.Recordset.Clone 

как у вас несколько экземпляров формы будут работать с одним публичным рекордсетом.