How to Detect a Loading Cursor

I have experimented with identifying the current cursor.  While it is theoretically possible in Windows applications I would advise against that approach.
The suggestions for using a WaitWindow or WaitProperty are the best way to go.  As suggested, you can wait for a particular control (e.g. button) to become enabled with WaitProperty.  Alternatively, you may wait for a new window/dialog to open with WaitWindow if that applies to your situation.  

Here is a VBScript example where I've waited up to 2.5s for a button to become enabled before proceeding:

Call o_SavBtn.WaitProperty("Enabled",True,2500) 'Wait for the button to be enabled

Below is some VB code from my attempt using the Win32 API to identify the current mouse cursor in case you want to go down that rabbit hole (not advised).  This is from several years ago.  I can't remember if I ever got it working.

Function getCurrentCursor(wndObj)
  Dim pid, tid, crsr     
  pid = Win32API.GetWindowThreadProcessId(wndObj.Handle, Nothing)
  tid = Win32API.GetCurrentThreadId
  Call Win32API.AttachThreadInput(pid, tid, True)
  crsr = Win32API.GetCursor
  Call Win32API.AttachThreadInput(pid, tid, False)
  getCurrentCursor = crsr
End Function

Function getCursorType(id, global_cache)
  Dim res
  res = id
  Select Case id
    Case 65541 res = "Arrow"
    Case 65541 res = "Move"
    Case 429134809 res = "Horizontal resize"
    Case 13569245 res = "Motor"
    Case 25758991 res = "Utility"
    Case 256118743 res = "Bus"
    Case Else res = "Other"
  End Select
  getCursorType = res  
End Function