Pass token and external ID with web service call

I'm connecting to a web service API and I need to pass a token and external ID (which changes based upon certain HL7 field) to send the messages. Is there an easy way of doing it?



Here's the sample envelope:



<!--Optional:-->

<con:token>?</con:token> (one token for this connection)

<!--Optional:-->

<con:externalKey>?</con:externalKey> (this changes based upon certain HL7 field)

<!--Optional:-->

<con:base64String>?</con:base64String> (Base64 encoded HL7 message)



I'm using:



Mirth Connect Server 3.0.2.7140



Built on April 15, 2014



Thanks

Pass token and external ID with web service call