Please help me with the regular expression for the password policy mentioned below:-
The password length should at least be 8 characters. It should be a combination of at least any two of the given sets.
a. Set of alphabets a-z, A-Z
b. Set of numerics 0-9
c. Set of special characters ~!@#$ etc.

I recommend that you search the 'Construction Advice' forum as there are many examples of password validation given there. Also in the same forum is a sticky name (http://regexadvice.com/forums/thread/43218.aspx) that explains the basic information we need to properly answer your questions. It is particularly important in this case as there are several different techniques that can be used that depend on  the regex engine and programming language that you are using.

Susan