Custom Sort Macro - Update on Data Entry

So my friends and I have a lot of time this summer, and we plan on playing out a mock world cup on FIFA 2010. I created the attached rudimentary spreadsheet that can keep track of stats and standings and stuff like that. I am looking for a way to automatically sort the standings (on the Group Tables sheet) as I enter scores into the Group Stage schedule on the Group Stage sheet (the long skinny table on the left). The intent is to sort each group first by PTS, then GD, then GF, and finally GA column. However, I'm not great with the programming so I was hoping someone can give me a hand. Is this possible to do? Or will the ongoing sorting function mess with the relative cell formulas?

Another issue I'm having recently is using the custom sort function. I tried to sort Group A using the custom sort of first PTS, then GD, then GF, and GA using a custom sort. But when I hit sort, the results aren't even close to what they should be, and they keep changing even though I'm applying the same sort over and over again. Give it a shot and see if you understand my issue.

Thanks for anybody who can help me out on this ridiculously irrelevant project I have saddled myself with.