[Small Basic w/ Data Extension] This will move the GameWindow using the numpad - arrows move the window by 10 pixels, [5] centers it and [7] puts it to coords [0,0]. Every second, the code checks if the window is outside the screen, and warps it back in a way so that it's fully visible. It also accounts for the taskbar.

GameWindow NumPad move.sb

' settings
includeTaskbar = 1
taskbarHeight = 30
gridSize = 10

GameKeyboard.KeyDown = boop

Sub boop
  If GameKeyboard.LastKey = "NumPad8" Then 'up
    GameWindow.Top = GameWindow.Top - gridSize
  ElseIf GameKeyboard.LastKey = "NumPad4" Then 'left
    GameWindow.Left = GameWindow.Left - gridSize
  ElseIf GameKeyboard.LastKey = "NumPad6" Then 'down
    GameWindow.Left = GameWindow.Left + gridSize
  ElseIf GameKeyboard.LastKey = "NumPad2" Then 'right
    GameWindow.Top = GameWindow.Top + gridSize
  ElseIf GameKeyboard.LastKey = "NumPad5" Then 'center
    GameWindow.Left = (Desktop.Width/2)-(GameWindow.Width/2)
    GameWindow.Top = (Desktop.Height/2)-(GameWindow.Height/2)
  ElseIf GameKeyboard.LastKey = "NumPad7" Then 'top left
    GameWindow.Top = 0
    GameWindow.Left = 0
  EndIf
EndSub

Timer.Interval = 1000
Timer.Tick = check

Sub check
  If includeTaskbar = 1 Then
    If GameWindow.Top < 0 Then
      GameWindow.Top = 0
    ElseIf GameWindow.Top > Desktop.Height - GameWindow.Height - taskbarHeight Then
      GameWindow.Top = Desktop.Height - GameWindow.Height - taskbarHeight
    EndIf
  Else
    If GameWindow.Top < 0 Then
      GameWindow.Top = 0
    ElseIf GameWindow.Top > Desktop.Height - GameWindow.Height Then
      GameWindow.Top = Desktop.Height - GameWindow.Height
    EndIf
  EndIf
  If GameWindow.Left < 0 Then
    GameWindow.Left = 0
  ElseIf GameWindow.Left > Desktop.Width - GameWindow.Width Then
    GameWindow.Left = Desktop.Width - GameWindow.Width
  EndIf
EndSub

'by matojeje
'cc-by