autochic,

I don't think that you need to have the complexity of an sControl for this.  You would be able to use a custom link as long as you are creating the custom object from the case.  Below is some instructions for creating something like this.  Please let me know if you have any questions or need help.

A Custom Link is a hyperlink on a record in Salesforce that, when clicked, will open up a different web page. You can use a Custom Links in Salesforce to trigger the creation of a new Salesforce record from within an existing record. By customizing your Custom Links you can pre-populate the newly created record with information from the existing record.

To create a Custom Link:

1. Create a new record by clicking the "New" when you are in the new record’s tab.

2. Copy the URL from the address bar when in the edit screen, it should end in “retURL=%2F001%2Fo”

3.Click on:

Setup | App Setup | Customize.

4. Click on the type of record on which you want the link to be displayed.

5. Click on "Custom Links". Click on "New".

6. Type in your Link Label and click "Next".

7. Paste the copied URL into the Link URL field.

You can now begin customizing your URL to propagate fields on your new record with the values on your existing record.

8. At the end of your URL type in an ampersand (the & symbol) followed by the name of the standard field you want to propagate.

NOTE: The name of a field is not necessarily the same as the field label displayed on a record.
NOTE: The easiest way to find out the target field name is by using Firefox. Go to the new record using the instructions above and then right-click anywhere on the screen. Click on the form tab and then wait for the third object to populate. Click on it and all the field names will be shown. You will have to do some testing with the link to find out which field label goes with which field.
NOTE: For custom fields, you must use the field ID instead of the field name. A field ID can be found by viewing the source code of a webpage on which that field is displayed. A field ID can also be found at the end of the URL on the Edit page for that field in setup.

9. After the Name of the field, type in an equals (the = symbol) followed by the value you want entered in that field. You can type in the actual value you want propagated, such as a word or number, or you can pull data from your existing record. To pull data from your existing record the value would be the Merge Field Name.

Sample: (will create a new lead from lead object):

https://na1.salesforce.com/00Q/e?retURL=%2F00Q%2Fo&name_firstlea2=[Mail Merge Name]&name_lastlea2=[Mail Merge Name]&lea3=[Mail Merge Name]&lea14=Hot

To propagate more than one field just repeat steps 8 and 9 as needed.