Writing to SAP from VB

Hi,

I have a problem when a try to write to SAP from VB, her is my code:

Set R3 = CreateObject("SAP.Functions")
Set fn = R3.Add("Z_BAPI_ZPTIME_CONFIRMATIONS")

Set orderno = fn.Exports("AUFNR")
orderno.Value = "51018700"

Set v_process = fn.Exports("PROCESS")
v_process.Value = "RUN"

p_result = fn.Call

When the program assign the first value the program stop and send the following message:

"Error 91: The type object variable is not assigned or established"

Can some help me with this issue.

Thanks

M. Roldán