How to dynamically change an Icon in the systray

Does anyone know how to dynamically change an Icon placed in the systray for a program. For example I would like to change the icon in the systray depending on if the program is enabled or disabled.... Any help would be great...

here is the UDT

Type NOTIFYICONDATA
LStructureSize As Long
hwnd As Long
lID As Long
lFlags As Long
lCallBackMessage As Long
hIcon As Long
sTip As String * 64
End Type

here is the API function
Declare Function Shell_NotifyIcon& Lib "shell32.dll" (ByVal lMessage&, NID As NOTIFYICONDATA)

some constants

Global Const NIM_ADD = 0&
Global Const NIM_DELETE = 2&
Global Const NIM_MODIFY = 1&
Global Const NIF_ICON = 2&
Global Const NIF_MESSAGE = 1&
Global Const NIF_TIP = 4&
Global Const WM_MOUSEMOVE = &H200
Global Const ABM_GETTASKBARPOS = &H5&

Global Const WM_LBUTTONDBLCLK = &H203
Global Const WM_LBUTTONDOWN = &H201
Global Const WM_LBUTTONUP = &H202
Global Const WM_RBUTTONDBLCLK = &H206
Global Const WM_RBUTTONDOWN = &H204
Global Const WM_RBUTTONUP = &H205
Global Const SW_SHOWNORMAL = 1
Global structNotify As NOTIFYICONDATA

code to add the icon
structNotify.lID = 0& ' increment this to create new instances(more than one icon)
structNotify.lFlags = NIF_ICON Or NIF_MESSAGE Or NIF_TIP
structNotify.lCallBackMessage = WM_MOUSEMOVE
structNotify.hIcon = Image6.DragIcon
structNotify.sTip = "TIP text" & Chr$(0)
ltemplong = Shell_NotifyIcon(NIM_ADD, structNotify)

code to remove the icon at shutdown
structNotify.lID = 0&
ltemplong = Shell_NotifyIcon(NIM_DELETE, structNotify)

code to change the icon
structNotify.hIcon = Image2.DragIcon
ltemplong = Shell_NotifyIcon(NIM_MODIFY, structNotify)

hopefully this is enough to get you going
I use this to keep our corps stock info dynamically updated in the tray from an internet feed. unfortunately each number had to be a separate icon