If you have LabVIEW, you can create a user step to perform the conversion in version 7.0. Sound and Vibration 2009 has a checkbox in the Frequency Response configuration page to export the real and imaginary components. Short of upgrading SVT, you can also install the evaluation version of NI LabVIEW SignalExpress 2009, and this will also upgrade the Frequency Response Step which is shared between the two products (but then you don't get all the other features that were also added in SV 2009).
Here are some links that may be useful to help decide whether you want to upgrade:
http://www.ni.com/soundandvibration/
http://www.ni.com/labview/signalexpress/
Doug
NI Sound and Vibration