Calling a userform and returning a value

You can manage to do this without the use of public variables.

There appears to be a difference between show/hide and load/unload.

If you hide a form while it's still loaded it won't be cleared out, so you can reference the state of the controls on the form.

For example I was using a date picker (called DTPicker1) on a form, my code in the module looks something like this:

Dim NewDay As Date

Load FrmDayPicker
FrmDayPicker.Show

NewDay = FrmDayPicker.DTPicker1.Value

Unload FrmDayPicker

Debug.Print NewDay

On your form you can just use Me.Hide insteaded of Unload Me and this should work

Remove Dim bool As Boolean from the userform code area and declare it in the module as shown below

This is how your Code in the module would look like

Public bool As Boolean

Sub Auto_Open()
    '
    '~~> Rest of the code
    '
    UserForm1.Show

    If bool = True Then
        '~~> Do Something
    Else
        '~~> Do Something        
    End If

    '
    '~~> Rest of the code
    '
End Sub

How about using a function instead of a sub?

Function loginbutton()
  ' your code

  loginbutton = bool
End Function

Now in your calling code you can test for true/false

if loginbutton() then
  'true responce
else
  'false responce
end if