Is it possible to specify OGNL expression as input parameter for custom data store (CustomDataSourceDriver implementation)?
PingFederate 7.1.2
no but there's an (unsupported) custom OGNL datasource that can be used as an intermediary datasource to transform attributes in to a form that is useful for your own, consecutive datasource, see: https://code.google.com/p/pingfederate/source/browse/trunk/datasource/ognl/src/com/pingidentity/datasource/OGNLDataSource.java