These are the main supported files that Line Count Manager can open: Doc, Docx, XLS, XLSX, PPTX, PPT, PUB, PDF, TXT, XML, HTML, INI, CSV, LOG. If the WordPerfect 10 is capable of exporting to one of these files, then yes, you can use it but not in the application directly. You have to use WordPerfect, export the file to one of the supported files and then load it into the Line Count Manager.
For additional information, use the following website:
http://www.windowindia.net/line-count-manager.html