If you don't need to convert the variable to a date but want change the WHERE clause you could replace the date value with the equivalent string by using macro code. So one of these:
where Date2 GE "%sysfunc(intnx(day,%sysfunc(today()),-3),yymmddn8.)"
where Date2 GE "%sysfunc(putn(%sysfunc(today())-3,yymmddn8.))"
The GE will work because strings in YYYYMMDD order sort lexicographically in the same order as the dates they represent sort chronologically.