find elements within ls-dyna .k file within certain coordinate range

Hello,

i need to find elements within a certain coordinate + radius out of ls-dyna k files. My problem is similar to the already existing function "findelements", but i cant import the k-file mesh as a pde object...

i already imported the k file data to the x,y and z coordinates of the nodes and the node ID's belonging to the elements.

My first approach was to search for nodes within my circle and select all elements with this node. But as you can see, at least 0 or 4+ elements are always hit, which is wrong (sometimes)...

My questions are:

1) Does anyone knows how to convert dyna k files to matlab mesh objects?

2) Does anyone has a better idea for an algorithm to search for elements with the given informations?

thanks in advance

edit: each element is described by 4 nodes at the corners, each node with x,y and z coordinates.