How to set Prepared Property to a value from a previous DataSource step?

I'm trying to create a DataSource jdbc step that takes the value of a prepared parameter from a prior DataSource step.

The SQL looks like 

Select tblPersonStatus.PersonStatus as PersonStatus
From  tblPersonStatus where tblPersonStatus.PersonID = :person

if I set a PreparedProperty name person to a specific value that exists in the db like 12234, then the data log populates and subsequent steps that use the PersonStatus property work.  However, if I try to set the PreparedProperty dynamically to the value of a property from a previous DataSource step (in this case reading from an Excel file) like person  {TestCase#PersonID} then it doesn't work, the data set comes back empty and subsequent steps see no value in PersonStatus.  The DataSource step to load the person id itself looks fine, and the Data Log shows the contents properly.

Does the value of a PreparedProperty have to be a fixed constant?  Do I have the syntax wrong?