Can I restrict the number of Post Journals submitted by a user using a Custom Data Security Policy?

Summary:

We would like to restrict users to limit the number of Journals they can submit for posting during any given session. We received the following suggestion at Open World:

Build a custom role (which we already have)
Define a Custom Data Security Policy
- Database Resource: Journal Entry
- Condition: define a custom condition to limit the posting, Use a condition such as Number of Journals <= limit value
- Data Set: specify a data set that restricts the number of journals a user can post in a single session (example, Journal Batch Count <= 5).

Unfortunately with our current version of Fusion, "Journal Entry" is not an available Data Resource, Data Set options are select by instance set, select by key or all values, not something I can customize, and the Conditions are based on a pick list conditional to the Data Resource/Data Set values chosen.