Wildcards are not supported in current version of Discovery. There is only option to create text file that contains all IP’s and use Bulk Upload selection method like:
We currently don't support wild carding in discovery, only workaround I can think of is take the first address in a wordpad and do a find-replace up to where you want to discover through and then paste them into the bulk upload section of discovery
The same thing can be done easily with Excel. I've done it a lot that way. Create a list of what you need and then save it as a text file. With a little tweaking, you can create these kinds of lists very quickly.