Modification to do substring search?

[swimmer]

Would it be very hard to modify the search function to do a substring search? 

Or make it a check-box option?   (e.g. "Make the search to be a substring search"]

The purpose of the eventual [SMF] forum is for me and maybe 1 or 2 other people to log our daily activities.  I would like the search function to find results for "cardiovascular" even if I only asked for "cardio" or "vascular" --or even "vasc". 

And because it's going to be a very few users, an expensive search ("expensive in terms of CPU time") is not a big deal.

[swimmer]

Never mind.   

I installed SMF and found out that the default behavior *IS* to do substring searches!  Good job guys.  Am very happy.