How can I select which lines to import from a txt file?

For example:
txt file
A;1;100;100
A;2;150;200


B;1;200;300
A;3;010;020
C;1;500;100


I need to import lines starting with "A" to a worksheet named "A", lines starting with "B" to a worksheet named "B" and so on.

Anybody can help me?

Thank you.