Powershsot S100 is available - minor difference in aperture specification but same zoom range - implying that the elements may be the same. Could serve for your purposes and works well for my S100.
I use the S100 lens profile for my S120. I haven't done any extensive tests to see how accurate it is but it seems to be ok, especially the vignette correction.
Tried the S100 lens profile and it seems to work OK with my S120. Thanks.