In the audio tab of the element you should be able to right click on the top of the tree and add another audio element. This will allow you to concantenate static files with say it smart applications. I use this all the time to do cofirms on digit entry say for instance you are capturing a phone number.
 
audio item 1 (1000.wav) = You entered
audio item 2 (SayItSmart DigitbyDigit) = 8005551212
audio item 3 (1002.wav) = Is that correct?
 
You just need to cut your static audio file up into multiple files so you can wrap your Say-It-Smart prompts around it.