Enterprise Vault 11 search from Microsoft Access

Hi everybody,

we are using a self programmed Access Tool for Ticket Process.

For this, im also gathering the inbox of a support Mailbox to create tickets out of them.

Now i want to search within the Vault of this support Mailbox (Enterprise Vault 11.0) for a given reference Number.
And show the results as a "history of communication" tab for each ticket.

I already tried to search throug the same way as Im gathering the Mailbox:

Set ns = Session.Application.GetNamespace("MAPI")
Set folder = ns.Folders(vault).Folders(Folder)

But its very slow. Each folder in the vault contains about 20.000 Mails.
On some tests it took me about 30 seconds to search for a reference number.

Do you know a way to search within the vault with VBA which is faster than the way through Outlook?

Thank you very much in advance.