Hi Alex, there isn't any built in method for that currently. There is a plug-in here which works for selecting solids that are intersected or contained by a closed curve though: http://moi3d.com/forum/index.php?webtag=MOI&msg=8088.5
Hi Michael - thanks for that thought i had seen it pop up before - I cant get it work with V4 - I have the curve preselected and then run the script but nothing happens.