Hy, it looks like it is not possible to search for computers which hasn't connected to the ocs server for at least 1 month from now.
That is not the full truth, but you can do only a custom search with a specific date. So as a result the search is not usable for dynamic groups - because a hard coded date is used.
It is not possible to create a search in a way that the actual date will be calculated and then a dynamic group can be created from that search.
Then you can search for for all Windows Computers which aren't connected for a specific time - create a dynamic group from that search - and after all you can look at any time if there is a computer in that group which hasn't connected for x months
If that would be possible in future versions that would be fantastic.