I've moved your post to the Developers' Forum. You are likely to get the attention you seek, and help relies to questions here... It is possible to write Ruby whch will read in a file, from that make geometry, and then export data back into a file... A few tips... There are some importer Plugin examples you should find and study... It's much easiest to use 'plain text' CSV rather than binary XLS etc... Obviously the file's exact format needs to be consistent and readily readable - usually points are make X,Y,Z one per line in the file, but if you want to define lines, then perhaps, X1,Y1,Z1,X2,Y2,Z2 - i.e. the line's [aka 'Edge'] start and end one per line in the file. You also need to consider the 'units' the file in in and how that translates to SketchUp - which always use inches as its base-units... There are also already some Plugin examples of 'cut-list'and similar exporters [CSV]...