Removing the Title bar of external application using c#

Question

My application starts up another external application.

I want to remove the title bar of this external application once it has started.

Is this feasible, and

Answer 1

Python version of Alex's answer if someone else needs:

import win32gui

#  get a handle to the window
windowHandle = win32gui.FindWindowEx(None, None, None, "Untitled - Notepad")

GWL_STYLE = -16  #  see https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setwindowlonga

#  get current window style
currentStyle = win32gui.GetWindowLong(windowHandle, GWL_STYLE)

#  remove titlebar elements
currentStyle = currentStyle & ~(0x00C00000)  #  WS_CAPTION
currentStyle = currentStyle & ~(0x00080000)  #  WS_SYSMENU
currentStyle = currentStyle & ~(0x00040000)  #  WS_THICKFRAME
currentStyle = currentStyle & ~(0x20000000)  #  WS_MINIMIZE
currentStyle = currentStyle & ~(0x00010000)  #  WS_MAXIMIZEBOX

#  apply new style
win32gui.SetWindowLong(windowHandle, GWL_STYLE, currentStyle)