How to allow users to update only comments in time entries

Hi expert,

I have a requirement to allow users to only update comments on timecards (Time Entry).

I am trying to figure out a way to achieve that through Time Entry rule however I'm facing some limitation:

• How to get TM_REC_ID and TM_REC_VERSION in the Time Entry Rule Fast Formulas
• How to get Old vs New Value of all attributes, date and measure info in the Time Entry Rule Fast Formulas

Thanks!