Which summer program sounds more appealing to college admissions?

Hi! Next year, I am planning to either attend a one-month long German exchange program in Germany where I will stay with a host family. My other option is doing research and exposing myself to engineering more at (hopefully) UCLA HSSEAS. I want to make myself a more interesting applicant by doing 4 years of German for my foreign language requirement and by attending the exchange program, allowing me to talk about it in my personal statements, but should I do that over the engineering research programs available? My dream is to attend UCLA under mechanical engineering.