Welcome to the swamp.
Take the lisp file ( *.lsp ). Copy the two codes, within the second post in this thread, into the lisp file. Save that. Take the dialog file ( *.dcl ), and place that within a folder that is within the support paths. Then you load the lisp. ' Appload ' or ' ap ' should show the dialog box to load the lisp file. Then select the *.lsp file. Once it's loaded you can use the commands that it defines, which is called out in the second post also.
If that doesn't help, tell us what you have tried, and what error messages are shown.
I don't think there is another version of the code ( unless Joe has posted his, but that would most likely be the same complexity ), and I have not rewritten it in lisp.