I need to get UDP traffic for a specific host from searches. How do I configure this or search
I'd recommend looking at the Splunk Stream add on. This will allow you to capture network traffic over the wire and filter based on transport type, application, dst/src port etc.
http://www.splunk.com/en_us/products/splunk-app-for-stream.html
Do you know which host you're looking for? Do you know if there's a specific index your UDP data goes into, or if there's a way you're flagging data that you're collecting via UDP?