How to set the start date on a pay element fed from Benefits

Summary:

Advice required on how to set a specific start date on a pay element after a selection is submitted from Benefits.

Content (required):

We have a benefit plan for Private Medical Insurance. This plan is assigned to the employee via a new hire life event, with a start date the same as their hire date. The enrolment window is open for 90 days.

We want the pay element to create on the date the employee makes their submission, rather than the start date of the associated life event.

We have tried a number of the options in the list 'coverage start date' but the closet we have gotten is about 8 days prior to the actual submission date, eg, submitted 24.08 and pay element assigned on 16.08.