"itisbeyondmypower" 不是一个正确的英文句子，正确的表达应该是 "It is beyond my power." 或 "It is beyond my ability."
因此，你可以将 "itisbeyondmypower" 改为 "It is beyond my power." 或 "It is beyond my ability."。例如：
1. It is beyond my power to help you with this task.
2. I'm sorry, but it is beyond my ability to solve this problem.