Thank you for your reply. That worked, but I think I must find another location to place it because the LISP program which prepares the drawing did not seem to finish before AutoCAD shutdown. Or at least when I opened it up the drawing was missing quite a few lines which would normally have been there.
I tried using System.Threading.Thread.Sleep(10000) and that seemed to have helped but one of the blocks which gets inserted is all out of scale. I will have to play around with this some more but many thanks for your reply.