The "Unmanaged Devices" canned report can't be scheduled, and that limitation would impact any copies of it as well.
Thanks rdavidson. I've been meaning to get back to you on this, but it looks like someone already marked it as the correct answer. I've been working on making my own version of this because I find the report so useful, but it is tedious to manually run it.
So, if anyone needs a way around this, I made a SQL query that does the same thing and strips out a lot of the excess (for my purposes) information. I then translated this query into a SQL job that transforms it into a table and emails it on a monthly basis. Anyway, here is the query.
LEFT OUTER JOIN DEVICEGROUPINFO A1
ON A0.DEVICEGROUPINFO_IDN = A1.DEVICEGROUPINFO_IDN
(A0.NODENAME IS NOT NULL OR A0.IPADDRESS IS NOT NULL OR A0.PHYSADDRESS IS NOT NULL)
and A1.GROUPNAME = 'Computers'
order by GROUPNAME
Thanks again for your help with this.