SQL Call on prepared stament

[botatun]

I try to call my RPG program from Excel to update file with info on spreadsheet.
It works, but I hardcoded parameters for call statement.
now I need to get back error message. I am not sure how to do it. This is what I have now:

cmd.CommandText = "call VbLib.ITEMBSR03(?, ?)"
cmd.Parameters.Append cmd.CreateParameter("ItemBSR", adVarChar, adParamInputOutput,
Len(sAs4Param), sAs4Param)
cmd.Parameters.Append cmd.CreateParameter("Error", adVarChar, adParamInputOutput, 1000,
sError)

Set rs_Update_BSR_Level = cmd.Execute()

It give me a message SQL0204: VbLib.ITEMBSR03 type * not found.
I think it happened only because parameters for call set up incorrectly.

How to correct them?

Vadim.