THERMAL BREAK INFILL - NYPA

I AM LOOKING FOR A PRODUCT TO INFILL A GAP WHERE GLAZING IS BEING REMOVED TO CREATE A THERMAL BREAK IN AN EXISTING STAINLESS STEEL WINDOW WALL. WE WILL BE INSERTING NEW THERMALLY BROKEN FIXED WINDOWS WITHIN THE EXISTING DAYLIGHT OPENINGS AFTER THE GLAZING HAS BEEN REMOVED. PLEASE HELP. THANK YOU.