Destroying Amalek

A few weeks back we discussed the question of can women carry guns. Some of you apparently thought that was random, but HalachaBoy in his infinite wisdom had the following up his sleeve, so sit back, relax and prepare for battle: As this week is the Shabbas before Purim we read Parshas Zachor. The Sefer HaChinuch (which lists all 613 mitzvos) writes that there is a positive commandment at all times and at all places to kill Amalek. The Sefer Hachinuch, however, does not mention that woman are commanded in this mitzva. [Editor's Note: We assume that woman ARE commanded in this mitzva and thus they should go to shul on Shabbas to hear the laining and have in mind to fulfill there mitzva through the reading of the torah]. Why would woman not be obligated in such a mitzva? The Avnei Nezer in trying to understand the the Sefer HaChinuch's exemption for woman opines that killing Amalek is a Mitzvas Esey Sh'Hazman Grama, a positive commandment that is time bound. Since we know killing is forbidden on shabbas (it's in the category of Shecita, slaughtering), and killing Amalek is a positve mitzva- perhaps we can say woman are exempt from this mitzva because since it can't be done on Shabbas, woman don't even have to do during the week (think tefillin, ladies) However, there is one rather large problem. In dealing with the obligation to kill and destroy the Seven Nations that occupied Israel when the Jews entered with Yehoshua, the Sefer HaChinuch explicitly says that woman are required to fight in such battles- even a Kallah from her Chuppah is required to fight. But if woman are required to fight the Seven Nations, and we don't say Mitzvas Esey Sh'Hazman Grama, how could we say it by Amalek?? This is a blatant contradiction in the Sefer HaChinuch! In the spirit of Purim, perhaps, the Avnei Nezer replies that it is not a contradiction the reason Hashem commanded us to kill the seven nations was for if we didn't and we lived with them as neighbors we would eventually start worshipping their idols, intermarrying and doing all the good stuff they did. So Hashem required us to kill them, but killing them was not a requirement in and of it self, it was a means to end, to achieve a society free of distractions and idolatry. So, in a sense the killing of the seven nations is actually a Melacha She'ano Tzricha L'Gufo, which is allowed on Shabbas. (the classic example of this digging a hole because I want dirt, the melacha is plowing- but here I don't care to plow, the plowing is just a means to an end of getting me dirt). Since this type of Melacha is not assur on Shabbas, woman are required to partake in the battle against the Seven Nations because it is not a time bound commandment. However, by Amalek, the commandment to kill and destroy them is the whole point. As destroying them is the whole goal it is bonafide Melacha and is assur on Shabbas- thus woman are exempt because Mitzvas Esey Sh'Hazman Grama.