I am new to ADO so if someone can help me out.
If I run a simple query it works but if I use parameters then my execute fails.

pCmd->CommandText=("SELECT SLSTCAE.AUTH_RETURN_DESC FROM SLSTCAE WHERE (AUTH_RETURN_ID = '?')" );
pCmd->Parameters->Append(pCmd->CreateParameter(_bstr_t,"AUTH_RETURN_ID"),adInteger,adParamInput,4,CComVariant(ReturnCode,VT_I4)));
pCmd->Parameters->Append(pCmd->CreateParameter(_bstr_t(vtValue),adBSTR,adParamOutput,30));

pCmd->Execute(&vtEmpty,&vtEmpty2,adCmdText);