我代表学校欢迎你的到来用英语怎么说

可以说 "On behalf of the school, I welcome you." 或 "I speak for the school in extending a warm welcome to you."
这句话的来源是因为"on behalf of" 意思是代表，"extend" 意思是延伸， "welcome" 意思是欢迎。
一些例句：
On behalf of the school, I welcome you to our campus. (我代表学校欢迎你来到我们的校园。)
I speak for the school in extending a warm welcome to our new students. (我代表学校热烈欢迎我们的新生。)
On behalf of the faculty, I extend a warm welcome to our guests. (我代表教师团队热烈欢迎我们的客人。)