Need help creating an encoder (?)

[justapimp]

I have been assigned this project to create a dynamic key code and I don't have a clue about how I can get it done.

The problem:

I am given a 10 digit number like a phone number 5627775698 and I need to parse through the number and set every other digit to zero starting with the the first digit. Then I need to convert that number to Binary and apply a mask like 1111111111 then add the two numbers together.

I already know how to apply the mask and adding the two numbers together but I need a system or technique to solve the first part of the problem.

Any suggestion?

[ericstenson]

If it is always 10 digits, it's easy.

One way to do it would be to remove every other digit, then you end up with

Dim String1 as String = 1234567891
String1 = 0 & String1.Substring(1,1) & "0" & string1.substring(3,1) & "0" & string1.substring(5,1) ....
... that gives you the idea.

[justapimp]

I am using C# and I've tried to implement the method below but when i ran it, I got "0700000100 for this number 6784855146" Can someone point out why I got this result?

protected void MaskMSID()
    {
        StringBuilder MSIDKey = new StringBuilder(this.MSID);
        for (int index = 0; index < MSIDKey.Length; index += 2)
        {
            MSIDKey.Replace(MSIDKey[index], '0');                
        }
        this.MSID_Mask = MSIDKey.ToString();
    }