One way is to use the numeric keyboard function - with my Toshiba using the Fn key+F11 means that part of the key board can be used to for numerical input and you then use the values as given here
http://tlt.its.psu.ed...s/codealt.html#accent to input the appropriate - you would need to check your laptop manual for which function keys you would need to use.
e.g. to type in é (e acute) I turn the numeric on, keep the Alt key down whilst typing mkll (which are the keys for 0233 in the numeric layout part of the keyboard) and then turn numeric off.