Forms :: Hide Controls When A Form Is Opened Conditionally

I've searched and can only find information setting the visible property when selections are made on an open form--I want to set the visible property when the form is opened depending on which avenue the user chooses from the navigation form.

I have a navigation form (Form A) and a second form with a subform (Form B). The user will choose from a combobox, either an existing record or a new record on Form A. On Form A there are two buttons, one that will take the user to the correct record on Form B for editing and one that will open to a new record on Form B. Once Form B is open, all controls will be blank (if a new record is chosen) or with certain controls prepopulated if an existing record is chosen.

What I want to do is to hide controls on the main form (not the subform) of Form B if the user chooses an existing record. Form A's buttons work correctly to open Form B right now. I want to be able to hide prepopulated controls on Form B if the user chooses an existing record from Form A.

Here's the code I'm using to open Form B to an existing record. I'd like to set the visible property here if at all possible.

NOTE: "Form A" and "Form B" are not the actual names of my forms--it's just easier for illustration purposes here in my question.

Private Sub cmdAddLogEntry_Click()
DoCmd.OpenForm "Form B", acNormal, , "Activity_ID = " & Me.cboINum
DoCmd.Close acForm, "Form A", acSaveYes

End Sub