That's not impossible since the attributes of the entity are not stored in no particular order like columns of the datatable.
The closest thing that I could think of is declaring a readonly string array beforehand.
public readonly string[] accountAttrib = { "name", "accountnumber", "email", "website" };
Entity account = new Entity("account");
account[accountAttrib[0]] = "abc";
account[accountAttrib[1]] = "12345";
account[accountAttrib[2]] = "test@abc.com";
account[accountAttrib[3]] = "www.abc.com";
service.create(account);