Other than adding the number also to the beginning of the book title, at the moment, no. When series were first introduced, the title search changed into series, then title search. Kobo decided since this wasn't technically title search anymore, it was wrong and changed to be a simple title search. This aggravated many, but it also pleased others.
Most people agree that the best solution would now to implement a series search separate from the title search. Kobo has yet to do anything. But since series implementation is fairly new, it may be changed in the near future (we can hope!).
And no worries...I feel like I'm reinforcing the things into my brain that I'm likely to forget before too long...I happened to have done a lot of the things you are doing recently myself, so everything is still fresh in the old noggin.
