How to store a Google spreadsheet in Gmail folder so it can be accessed and updated from within Gmail?

A better way to do this job is to use the Google's Cloud Computing also called Google Docs. This shall help in doing your job indirectly

1. Visit www.docs.google.com.
2. Enter your username and password and then sign in.
3. On the left side of the site click on the upload image on the right side of create button.
4. Browse for the spreadsheet file and click on the option "Convert documents, presentations........format" and then click on the "start upload" button.
5. Now click on the spreadsheet you uploaded and edit it as per your needs. After finishing editing let the site save your spreadsheet. To the above centre of the site you can see your spreadsheet status. After the saving is done click on share button on the right top of the website and enter your email address.
6. Now to go back to your main google docs page click on the left top side of the site on left side of the name of the spreadsheet (a little back button comes up when you move your mouse the spreadsheet's name).
7. Now you can again visit the google docs site and edit whenever as you wish.....