Holes in complex surfaces

I created a surface in another program using a parametric equation in x,y,z.  Then it was imported as an IGES file.  It was lofted to a body.  Problem is that now I wish to place some holes in it.  I have created circle geometry on adjacent planes and tried to create holes thru all-no luck.  Created a cylindrical boss and put a hole thru it, didn't recognize the surface.  Tried projecting a curve on to it, didn't like that either, it is not cylindrical.  Any clues?

May have to create a mesh body and tug it or twist it into shape, but would like to keep what I have.

SolidworksSketching