How to decode and encode the content of IE cookie files?

I have this cookie file:

C:\Users\<username>\AppData\Roaming\Microsoft\Windows\Cookies\X6NIM8XR.txt

which has this content:

username
Wilhelm
<my website>
1600
707951488
30470522
845076939
30464487
*

So how can I decode/encode the cookie fields Secure, Expire and Modified from/to these numbers?

EDIT: Since I have noticed that changing the cookie value (e.g. from Wilhelm to John) in thisX6NIM8XR.txt file does not work: Is there a convenient command-line program which can:

• Get all fields from a specific cookie
• Modify specific fields of a specific cookie