I created a userform to show a progress bar when the macro is still importing sheets

The problem is the user can press the red [X] button that will close and interrupt the processing done.
Is there a way to hide this red button of doom so that potential users don't have any confusing buttons to click while it runs.
edit:
I have tried this
'Find the userform's Window
Private Declare Function FindWindow Lib "user32" _
Alias "FindWindowA" ( _
ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long
'Get the current window style
Private Declare Function GetWindowLong Lib "user32" _
Alias "GetWindowLongA" ( _
ByVal hWnd As Long, _
ByVal nIndex As Long) As Long
'Set the new window style
Private Declare Function SetWindowLong Lib "user32" _
Alias "SetWindowLongA" ( _
ByVal hWnd As Long, _
ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long
Const GWL_STYLE = -16
Const WS_SYSMENU = &H80000
and I used this on userform_initialize
Dim hWnd As Long, lStyle As Long
'Which type of userform
If Val(Application.Version) >= 9 Then
hWnd = FindWindow("ThunderDFrame", Me.Caption)
Else
hWnd = FindWindow("ThunderXFrame", Me.Caption)
End If
'Get the current window style and turn off the Close button
lStyle = GetWindowLong(hWnd, GWL_STYLE)
SetWindowLong hWnd, GWL_STYLE, (lStyle And Not WS_SYSMENU)
I am getting this error message

this code was taken from here. I don't know what I'm doing wrong and I already removed the comments. This is the simplest code that I found so I would like to integrate it to my userform. Any help is appreciated.