Problem With Sp_OAMethod

I am trying to call a working DLL from a stored procedure. The object is made, but when I invoke a method, I get an error message that I guess indicates that I am calling it incorrectly. But I can’t find what’s wrong:

The COM is TDMSQLUtil.dll and is registered on the server, and only has one class and one method.

Public Sub RemoveItems(ByVal ItemNumbers As String, ByRef Col1 As String, _
Col2 As String, ByRef Col3 As String, ByRef Col4 As String, ByRef Col5 As String, ByRef Col6 As String, ByRef Col7 As String, ByRef Col8 As String, ByRef Col9 As String)

I call it with:
1 ) Exec @HResult = sp_OACreate 'TDMSQLUtil.cHandleString', @Object out
(this does not return an error)

2) Exec @HResult = sp_OAMethod @Object, 'RemoveItems', @ItemNumbers, @Col1 out, @Col2 out, @Col3 out, @Col4 out, @Col5 out, @Col6 out, @Col7 out, @Col8 out, @Col9 out

The error I get is:
sp_OAMethod usage: ObjPointer int IN, MethodName varchar IN [, @returnval <any> OUT [, additional IN, OUT, or BOTH params]]

What am I missing? I followed the instructions in BOL, or at least, I tried to>

Any help greatly appreciated
Thanks,
Judith