>> ... and the file would have to be open to run the macro
>Isn't possible to run the macro after a new value is entered into a cell?
>Isn't possible to change the sheet name without do a save as?
>
>Because, I want to change de sheet name (or tab) immediatly after a new value is entered into a cell... I want the code is executed like a @sum() function. Isn't possible? I have tried to put my function into the cell, like a @sum() function, but nothing happen... That function works fine otherwise. Do you know why?

Changing a sheet tab is a whole lot easier than renaming a file, but I still don't know of any way to do it without making a macro. You could have your sheet contain the macro and have a button to run it right next to the value that gets entered. If you find a way for the trigger for the changing of the sheet name to be the changing of the value of a cell, I'll be surprised.

I'm surprised that it's the only thing you need a macro to do. Usually I have a "Preferences" or "Main" sheet where user enter several values. Then I have a button on that sheet that says something like "Create data sheet".

I've even made a sheet that you entered some initial info in a sheet called "Step 1" and had a button that said "Make step 2". It created the sheet "Step 2" that had info based on step 1 and that macro also created a button on the "Step 2" sheet that said "Make table." The user would press that button after they made their changes. Pretty neat if I do say so myself. Now, that's not just to brag. I'm just saying if the sheet comes from somehwere else, it is possible to have a macro that makes the button next to the value entered that does what you need.

I just had this thought. If it can be the first step, you could put in a macro that automatically runs when you open the sheet. It could open a window with "Please enter the name of the sheet tab" and the macro could change the tab to that value and if need be change the value of a cell too.