Consuming an external Web Service that requires User Name, PWD and API KEY

Hi,

I am trying to consume an external web service that requires ( for authentication) a user name, password and API Key. The three items were provided by the external system administrator. Now, even though I am able to consume it using SOAP UI tool but when invoking it from SAP I am not able to pass the API Key any where in the the ABAP code or in the logical through LPConfig or SOAMANAGER transaction. the API Key is part of the URL (https://address/HRIS/SOAP/Positn?api_key=2a3y4qeubgwpsbacdhg3tgcb). Kindly Help