Matthias,
His email is aluo_luosang@hotmail.com
I have done the trek a number of times, and left Dimaluo last week. I am doubtful that you will be able to trek the route in April as I think there will still be a ton of snow. However, Aluo will be able to give you a correct answer.
I am interested that you couldn't find any information about Aluo though. A just did a simple google search for "Dimaluo" and there are a host of entries with a tripadvisor entry (2nd listing) describing the trek and an angelfire site (6th entry) that contains his email address?