International Transfer Applicant: Good college mediocre high school gpa

<p><em>I posted this in another forum by accident please delete other one</em>
Hi,
I was thinking of transferring from a Canadian university to the business schools of either NYU, UPENN, MIT or Stanford's management science program. I write to inquire about my chances.
I can safely say that my resume looks fairly good: I have extensive leadership experience (am running a marketing research firm, held seminars in high technology start ups, helped establish a youth council in my city). College GPA for first year is about 3.8. Have yet to take the SAT.
My only problem is a relatively mediocre high school gpa. I averaged about 77% (86% senior year but has a 99% and a 95% for the only classes where I studied) How can I work around the fact that my high school gpa is relatively poor?
Since I am also an international student, I won't bother with scholarship thought. I, in all candor, "just want to get in". Can you please evaluate my chances.
Resume:
1) 3.8 GPA (engineering and business major switching to business major, usually 2-3 in class)
2) Founded marketing research firms for companies with teen customers has 3 employees and many contractors (I dont even count those now).
3) Helped found city youth cabinet (I can exaplain what that is)
4) Held seminars for local residents on started high technology (e.g. bio, telecommunication) businesses.<br>
5) Start non-profit in high school (small fundraising activities for sick children)
6) Started online card stores in high school
7) Other extras include:
-reporter for student newspaper,
-martial art competition
-volunteering in countless places (more than ten) .
Worry:
8)Mediocre High school gpa + international student
What are my chances at Stern, Wharton, Sloan and Stanford (management science)?</p>