Quotethe Open project dialog only allows you to select *iwp file
This is not really true, if you known the following trick:
Set focus to the file name editbox, select all (if something is there) and type
*.ebpthen press Enter key. From this point, the dialog will display only ebp files.
This trick I'm using to add .res files to a project. Menu->project->insert library->type unquoted "*.res"->press enter->browse and select the res file.