yes. in the subform's Current event, add the following code, as
Private Sub Form_Current()
Dim ctrl As Control
For Each ctrl In Me.Controls
Select Case ctrl.ControlType
Case acTextBox, acComboBox, acCheckBox
ctrl.Locked = Not Me.NewRecord
End Select
Next
If Me!ControlA.Locked Then Me!ControlA.Locked = False
If Me!ControlB.Locked Then Me!ControlB.Locked = False
End Sub
for ControlA and ControlB, substitute the names of the two controls you want
open at all times. the procedure looks at each control on the subform. if
the control is a textbox, a combo box, or a checkbox, then the code sets
Locked = True on existing records, and Locked = False on new records. then
the code checks the two "always open" controls, and unlocks them if
necessary.
hth