将正则表达式重新格式化为C＃逐字字符串文字

I have a regex pattern and would like to use the @ symbol in front of the string so that you don't need to escape the regex escape characters. When I try that I keep getting a compilation error saying "Only assignment, call, increment, decrement and new object expressions can be used in a statement". I am sure I need to remove the escape characters that I have in my string before I can use @. However I am not able to get it to work. Can someone help get the below string pattern modified to use @ at the start.I have a regex pattern and would like to use th