Add an ftp user from a client pc

I don't know if this is the right section, but here's my problem.

I need to create ftp users on my server windows 2003 from a client pc.

I made an asp page that calls a function of a dll written by me.

VB Code:

<%
 
dim obj
Set obj = server.CreateObject("esegui.funcEsegui")
 
 
Response.Write("Error Code: " & obj.runexe(server.mappath("eseguiftp.exe")))
 
%>

the dll code is this:

VB Code:

Option Explicit
 
Public Function RunExe(ByVal Filename As String) As Long
On Error Resume Next
 
Shell Filename
 
RunExe = Err.Number
 
End Function

On the server I have "eseguiftp.exe" with this code:

VB Code:

Private Sub Form_Load()
    
    Shell "CMD.exe /c MD C:\WEBDIR\FTP\myuser", vbHide
    Shell "CMD.exe /c cacls c:\webdir\ftp\myuser /R USERS /e", vbHide
    Shell "CMD.exe /c cacls c:\webdir\ftp\myuser /G myuser:f /E", vbHide
    Shell "CMD.exe /c net user myuser mypwd /add", vbHide
    
    End
    
End Sub

Now, when I open the asp page, on the server "eseguiftp.exe" is run, it creates the folder "myuser", but it doesn't add the user "myuser".

If I run "eseguiftp.exe" directly on the server by double-clicking it, all works.

Where is the mistake?