Need CryptCreateHash version of the HMACSHA1.ComputeHash .net function.

Here is the VB.net sample I am working with:

   Public Function aws_GetSignature _
       (ByVal Operation As String, ByVal TimeStamp As _
       DateTime) As String
   
       Dim strSig_Raw As String
       Dim strSig_UTF8 As Byte()
       Dim strSignature As String
       Dim objUTF8Encoder As UTF8Encoding
       Dim objHMACSHA1 As HMACSHA1
   
       strSig_Raw = "AmazonS3" & Operation & _
          aws_GetISOTimestamp(TimeStamp)
   
       objUTF8Encoder = New UTF8Encoding()
       strSig_UTF8 = objUTF8Encoder.GetBytes(strSig_Raw)
   
       objHMACSHA1 = New HMACSHA1( _
          objUTF8Encoder.GetBytes(m_strSecretAccessKey))
       strSignature = Convert.ToBase64String _
          (objHMACSHA1.ComputeHash( _
          objUTF8Encoder.GetBytes( _
          strSig_Raw.ToCharArray())))
   
       Return strSignature
   
   End Function

I have the ISOTimestamp, UTF-8 encoding, and base 64 functions working but need help with the HMACSHA1.ComputeHash function. How can I implement the HMACSHA1 function in VB6 using the CryptCreateHash Windows SDK function?

Kevin