Using XEnroll to create a PKCS10 with SHA-256 Hash Algorithm

Question

I am trying to create a SHA-256 PKCS10 using Microsoft´s CSP (Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)) but without success.

I have to do this using the XEnroll API (Windows XP / SP3).

Here´s the sample for generating a SHA-1 PKCS10 (works just fine!):

Set Enroll=CreateObject("CEnroll.CEnroll.2")
Enroll.providerName = "Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"
Enroll.providerType = 24

Enroll.HashAlgorithm = "SHA1"
req=Enroll.CreatePKCS10("CN=BLAH", "1.3.6.1.5.5.7.3.2")

WScript.Echo req

Any help will be welcome! Thanks!