I experimented a little with this (instead of HTTP post, I use FTP), but
when I try to send an ActiveDocument to my webspace, just nothing happens. I
can only get it to work when sending another file which is not open. So yes,
if you create a DocumentClose-event which opens another doc with the macro
and FTP the saved file from there, it should work.

Here's my code.

Option Explicit

Private Declare Function InternetCloseHandle Lib "wininet.dll" (ByVal hInet
As Long) As Integer
Private Declare Function InternetConnect Lib "wininet.dll" Alias
"InternetConnectA" (ByVal hInternetSession As Long, ByVal sServerName As
String, ByVal nServerPort As Integer, ByVal sUserName As String, ByVal
sPassword As String, ByVal lService As Long, ByVal lFlags As Long, ByVal
lContext As Long) As Long
Private Declare Function InternetOpen Lib "wininet.dll" Alias
"InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal
sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As
Long
Private Declare Function FtpPutFile Lib "wininet.dll" Alias "FtpPutFileA"
(ByVal hConnect As Long, ByVal lpszLocalFile As String, ByVal
lpszNewRemoteFile As String, ByVal dwFlags As Long, ByVal dwContext As Long)
As Boolean

Private Sub FTPUploadDocument()
   Dim hConn As Long, hAndle As Long
   Dim ftpSrv, ftpUsr, ftpPwd As String
   ftpSrv = "ftp.server.here"
   ftpUsr = "ur_id"
   ftpPwd = "ur_pass"
   hAndle = InternetOpen("WinWord FTP Demo", 0, vbNullString, vbNullString,
0)
   hConn = InternetConnect(hAndle, ftpSrv, 21, ftpUsr, ftpPwd, 1, IIf(True,
&H8000000, 0), 0)
   FtpPutFile hConn, "file.doc", "uploaded.doc", &H1, 0
   InternetCloseHandle hConn
   InternetCloseHandle hAndle
End Sub