See also → Special characters
(I. Macro · II. Extension "Compose Special Characters")
The advantage over "AutoCorrect Replace"
:
You don't need a space in front of the key combo for the special character.
Adapted explanation – sample: « »
«
= U+00AB LEFT-POINTING DOUBLE ANGLE QUOTATION MARK : left guillemet
»
= U+00BB RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK : right guillemet
I. Macro
Replace "Sub insert_integral"
with (e.g.) "Sub left_guillemet"
Replace "&H222B"
with "&H00AB"
Replace "Sub insert_integral"
with (e.g.) "Sub right_guillemet"
Replace "&H222B"
with "&H00BB"
II. Extension "Compose Special Characters"
A. Compose Special Characters (CSC)
Type: << → CSC shortcut
Result: «
Type: >> → CSC shortcut
Result: »
(my CSC shortcut: Alt+F8)
B. Compose Unicode Characters (CUC)
Type: 00AB → CUC shortcut
Result: «
Type: 00BB → CUC shortcut
Result: »
(my CUC shortcut: Alt+F9)

EDIT 2012-12-10
Don't forget to set (and type) a flag character for Calc, e.g.: *
(see the image above: Instructions · Spreadsheets).
OP: @ggbb84