Find out when a user certificate will expire

Does anyone know how I can find out when the certificate will expire for a user? I know I can get all certificates for a given user using the following code:

Set objUserTemplate = _
    GetObject("LDAP://cn=userTemplate,OU=Management,dc=NA,dc=fabrikam,dc=com")
arrUserCertificates = objUserTemplate.GetEx("userCertificate")

      

        
        
        
      

    

But how can I start polling the expiration date for a given certificate? I saw this Java code here: http://forums.novell.com/novell-developer-forums/dev-ldap/364977-q-retrieving-users-public-key-over-ldap.html .

X509Certificate cert = ( X509Certificate )it.next();
java.util.Date expires = cert.getNotAfter();
GregorianCalendar calNow = new GregorianCalendar();
GregorianCalendar calExp = new GregorianCalendar();
calExp.setTime( expires );
//issuerDN = cert.getIssuerDN().getName();
int daysTilExp = com.willeke.utility.DateUtils.daysPast( calExp );
long diffDays = com.willeke.utility.DateUtils.diffDayPeriods( calNow,
calExp );
if( diffDays <= 0 )
{
String mex = " Will expire in: " + diffDays + " days!";

      

        
        
        
      

    

but I'm not sure if I can use the method getNotAfter

in VB, or how I would go about doing it. Does anyone have any ideas? If at all possible, I would like to help fulfill this request in VBScript / VB.Net / VBA etc.

I found VBScript code here that seems to do what I am trying to accomplish, but seems quite complicated, the Java code seemed much simpler. Is there an easier way to make this request in some VB flavor?

From the cruto website:

On Error Resume Next

Const E_ADS_PROPERTY_NOT_FOUND  = &h8000500D
Const ForWriting = 2
Const WshRunning = 0

Set objUser = GetObject _
    ("GC://cn=MyerKen,ou=Management,dc=NA,dc=fabrikam,dc=com")
objUser.GetInfoEx Array("userCertificate"), 0
arrUserCertificates = objUser.GetEx("userCertificate")

If Err.Number = E_ADS_PROPERTY_NOT_FOUND Then
    WScript.Echo "No assigned certificates"
    WScript.Quit
Else
    Set objShell = CreateObject("WScript.Shell")
    Set objFSO = CreateObject("Scripting.FileSystemObject")
    strPath = "." 
    intFileCounter = 0

    For Each arrUserCertificate in arrUserCertificates
        strFileName = "file" & intFileCounter
        strFullName = objFSO.BuildPath(strPath, strFileName)
        Set objFile = objFSO.OpenTextFile(strFullName, ForWriting, True)

        For i = 1 To LenB(arrUserCertificate)
            ReDim Preserve arrUserCertificatesChar(i - 1)
            arrUserCertificatesChar(i-1) = _
                Hex(AscB(MidB(arrUserCertificate, i, 3)))
        Next

        intCounter=0
        For Each HexVal in arrUserCertificatesChar
            intCounter=intCounter + 1
            If Len(HexVal) = 1 Then 
                objFile.Write(0 & HexVal & " ")
            Else
                objFile.Write(HexVal & " ")
            End If
        Next
        objFile.Close
        Set objFile = Nothing

        Set objExecCmd1 = objShell.Exec _
            ("certutil -decodeHex " & strFileName & " " & strFileName & ".cer")
        Do While objExecCmd1.Status = WshRunning
            WScript.Sleep 100
        Loop
        Set objExecCmd1 = Nothing

        Set objExecCmd2 = objShell.Exec("certutil " & strFileName & ".cer")
        Set objStdOut = objExecCmd2.StdOut
        Set objExecCmd2 = Nothing

        WScript.Echo VbCrLf & "Certificate " & intFileCounter + 1
        While Not objStdOut.AtEndOfStream
            strLine = objStdOut.ReadLine
            If InStr(strLine, "Issuer:") Then
                WScript.Echo Trim(strLine)
                WScript.Echo vbTab & Trim(objStdOut.ReadLine)
            End If
            If InStr(strLine, "Subject:") Then
                Wscript.Echo Trim(strLine)
                WScript.Echo vbTab & Trim(objStdOut.ReadLine)
            End If
            If InStr(strLine, "NotAfter:") Then
                strLine = Trim(strLine)
                WScript.Echo "Expires:"
                Wscript.Echo vbTab & Mid(strLine, 11)
            End If
        Wend

        objFSO.DeleteFile(strFullName)
        objFSO.DeleteFile(strPath & "\" & strFileName & ".cer") 

        intFileCounter = intFileCounter + 1
    Next
End If

      

        
        
        
      

    

Update. I saw that I could import the certificate into the CAPICOM object to return the ValidToDate Property, but apparently the format it is stored in AD is not in the correct format as per this posting here: http: //www.powershellcommunity. org / Forums / tabid / 54 / aff / 4 / aft / 1639 / afv / topic / Default.aspx

Does anyone know what format is expected from the CAPICOM import function?