C# Regular expression for start and end text

Question

Hi

I am looking for replacing text in given file & I am looking for regular expression for replacing text, which matches below cases.

1. ORDER-abc.com
2. ORDER.abc.com
3. order-abc.com
4. order.abc.com
5. order-xyz.com

So, basically my regular expression is built on search start with order and ends with .com.
This is not a sensitive and text can present in both upper and lower case.

Please let me know the regular expression, which should verify in total text file.