Determining start date if I have the end date identified

Hi all, first time here and total excel newbie and appreciate in advance any help y'all can provide.

I am trying to create a formula where I take the date in column D (my end date) and subtract 14 business weeks. The sum of that would then be placed in Column C (my start date).

For example
Column C is the start date which is the sum of the date in Column D minus 14 business weeks. The result needs to be a day of the work week and also not fall on a US holiday (if possible) nor on a weekend (Sat/Sun).

Thanks!