how to enter the eli lilly elanco spinoff into quicken 2017

ref:  https://investor.lilly.com/news-releases/news-release-details/lilly-announces-final-results-elanco-exchange-offer

It appears to me Lilly may have taken some or all of your Lilly shares and exchanged them for Elanco shares,  I would not rely on the brokerage downloads to be accurate.  Their website information should be more accurate.

Q1:  How many Lilly shares did you have before March 11 and how many did you have after that date?  The difference would be how many you gave up in the exchange.  I would generally expect that to be an integer number of shares, but I could be wrong about that; you may have exchanged a fractional share.  

For each share of Lilly you surrendered in this exchange, you should have received 4.5121 shares of Elanco.  For example, if you gave up 11 Lilly shares, you would be due 49.6331 shares of Elanco.  

You need to determine the cost basis of the shares you surrendered.  That amount becomes the cost basis for the total (including fractional shares) shares you were due to receive.  This is supposed to be a totally tax-free exchange which is why your cost basis of the surrendered shares transfers to the new shares. 

In Quicken, I would:
1)  Enter a Remove Shares transaction removing the requisite number of Lilly shares that you surrendered.  I would select the lots removed.  I would note the dates acquired for those shares and the cost basis of those shares - by lot.  (I would think it would be your choice to specify the lots, but you should also review and understand what your brokerage has done so that the two of you are on the same page.) 
2)  Enter, for each lot of Lilly shares removed, an Add Shares transaction for the increased number of Elanco shares received.  Use the lot's acquisition date and cost basis within the Add Shares transaction.
3)  Once all the Add Shares are entered, Enter as Sell Shares of Elanco for any fractional share you were due but did not actually receive.  The Amount for this sale is the cash-in-lieu amount you received as part of this transaction. 

If by chance (unlikely I think) all of your Lilly shares were exchanged for Elanco shares, Quicken's Corporate Acquisition transaction should be possible.

HTH