Custom Fields in Recurring Donations

I have a pre-purchase question on the Recurring Donation’s add on.

We have Cause 1, Cause 2, Cause 3 can I use the Recurring Donation addon to allow people to select either Cause 1, Cause 2 or Cause 3 to give to on a recurring basis.

I have read through most of the documentation but nowhere do I see the ability to add a field to the Recurring Donation add-on.

From all the documentation I have read it seem the recurring donation option does not let you choose a Cause to give to or nominate a Cause.