Report Builder pass Relative Date slicer dates into parameter

I have created a Pixel Perfect report in report builder that has x2 DateTime Parameters (they use a date picker):

To Date

From Date

The tables query parameters use the date column in the connected Power BI Dataset.

My connected Power BI Report uses a relative date slicer to filter the report. 

I'd like to pass the relative slicer dates into the Pixel Perfect URL Parameters.

However I am unable to copy the DAX from the relative date slicer to create the query in report builder so I have just dragged in the date column.

Any suggestions on a work around is welcomed.

Thaanks.