RegEx Help Needed

Hi,

I'm awful with regular expressions most likely because I haven't spent much time writing them but I'd like to have one that does the following

Requirements

1. Must be a minimum of 7 characters

2. Must have at least 3 out 4 of the following

    2a) 1 Uppercase letter

   2b) 1 Lowercase letter

   2c) 1 Number

   2d) 1 Symbol

So I want to pass in a string, and then run it against a regex that does the above.

Any help appreciated

-ws