Find people on Twitter through e-mail csv import

Today you may give Twitter your login details to a few webmail services to search for your friends' twitter profiles.
But I use a local e-mail client, so this doesn't work for me.
I'd like to be able to upload a csv file with email addresses to twitter to get a list of matching profiles.
By the way, I'd use that function to get a list of matches for my gmail and LinkedIn friends, as well. (I'm simply don't want to give you my login details to my other accounts.)
(I know, that a weird workaround right now would be to sign up for a temporary account with gmail or Yahoo and upload my contact list there and then give you the credentials of this temporary account. But it shouldn't be to hard to make a more straightforward solution.)