This really depends what version of CFD you are running. Only the latest (2014) will be Creo compatible. For prvious versions, you would be best off opening the CAD in Inventor Fusion (free with Sim CFD) and launching from there.
This is from the CFD 2014 WIki: http://wikihelp.autodesk.com/Simulation_CFD/enu/20
Could you tell me if Simulation CFD 2012 can be launched from Wildfire 5 using the launcher which we originally received, for Wildfire 3? We have a single machine licence (not network).
The answer is yes, although you need the correct launcher for WF5, which you would likely not have right now. I do have a folder that contains all of the launchers up to WF5 and will email you this shortly.