Calling chm file from MS Word

I'm trying to display my compiled help file by calling it from MS Word 2000 but nothing happens. I'm using the coding copied below, which is working perfectly in MS Excel 2000. Have anybody any idea what the reason could be? I'm in desperate and urgent need for any kind of help with this problem (aint we all).

Public Const HH_HELP_CONTEXT = &HF
Public Const HH_CLOSE_ALL = &H12

Public Declare Function HTMLHelpStdCall Lib _
"hhctrl.ocx" Alias "HtmlHelpA" _
(ByVal hwnd As Long, ByVal lpHelpFile As _
String, ByVal wCommand As Long, _
ByVal dwData As Long) As Long

Private Sub cmdContextInteger_Click()
HTMLHelpStdCall 0, "PFBHelp.chm", _
HH_HELP_CONTEXT, 1030
End Sub