This sounds like something out of a horror film...... come meet me in Berlin, I will send you home in bits!
Do you have a number pad? Hold down alt and type: 132 137 139 129 You have to use number pad. Won't work with numbers above the letters.
In which case, I wouldn't be sending them home in bits, I would just be keeping them in my freezer in bits. And enjoying some lovely fried penis.
You can't just type the letter then follow it with a code (as far as I'm aware)- you type an alt code for the letter you want. e.g. alt131 gives you â, alt136 for ê . I remember a couple of them because I've used them a few times. Find what you want here: http://tools.oratory.com/altcodes.html
I just google the word I want and copy and paste it with the accents already on - easier for me than trying to remember which keys to hold down and which numbers to type etc.