Just a slight clarification - the number assigned to all entries should not be referred to as a Case Number. It would be another "Entry Number" - and those entries would then be selected for further processing - at that point getting the "Case Number".
What I meant is once they collect all the entries with the weird numbering (the one you got when you placed your original application, which is the one you use in their ESC system), they run their super smart computer and assign randomly a number to all entries, for each region. That is when you got your 2014EU0000xxxxx number. Everyone gets a unique number (you can call it a case number, a entry number or whatever you like). Then, if your rank number is below the cutoff for the DOS selection of your region, you are a winner. That does not mean you will be interviewed though as it depends if your number becomes below the cut off in the Visa Bulletin at some point in the fiscal year.
They selected 125k entries for DV14. They are supposed to notify all these selectees, as described in section (g) of 22CFR42-33:
"(g) Further processing. The Department will inform applicants whose petitions have been approved pursuant to paragraph (c) of this section of the steps necessary to meet the requirements of INA 222(b) in order to apply formally for an immigrant visa."
BTW, looks like for DOS you apply formally to an immigrant visa when sending the forms to KCC.