A common technique is to make use of a "metadata plugboard" to alter the title of a book to add-in additional info. I for instance have the following plugboard in effect
Code:
Format: epub
Device: KOBOTOUCH <-- This is related to the DRIVER being used; KOBOTOUCH is the basic driver; KOBOTOUCHEXTENDED is for the Kobo Touch Extended (ie the driver that changes a book to kepub format)
Source Template: {series:re(([^\s])[^\s]+(\s|$),\1)}{series_index:0>2s| - | - }{title}
Destination Field: title
What this does is to prepend an abbreviated form of the series name (1st letter of each word in the name), followed by a space, hyphen and space, then the two digit sequence # of a book in the series, and finally another space, hyphen and space before the actual title.
This has the effect of (for instance) changing
Harry Potter and the Philosopher's Stone,
book 1 in the
Harry Potter series to
HP - 01 - Harry Potter and the Philosopher's Stone. Additionally, a book NOT in a series is left as is.
This means that books when sorted by title on the Kobo appear in series order.
I also add "series" to the shelf definition field in the driver.
Conversely, if you just want the book number but NOT the series in the title, then set the template to
Code:
{series_index:0>2s|| - }{title}
For the book listed above this would change it's title on the device to
01 - Harry Potter and the Philosopher's Stone.