I don't write Spanish any longer. It looks to me as if you are trying to auto-fit text frames to the content. Is this document built using Data Merge, or some other method? You can "Fit Frame to Content," but it you cannot do it automatically during a merge. It will help us help you if you can give us more details about the project and which verion of InDesign, and what operating system, you are using.
I try to explain. I'm using Indesign CS3 in windows 7 system. I'm using data merge method with text formatted data (txt).
I have fields where I need to put names, this have diferents lenghts (characters). For example, need to place in the same mesure of field diferents names like "SUE" or "JOHN ANTHONY", I have the idea of any kind of system that adjust the font size depends the number of characters. I use the overset text option to repair, with the report that shows all the text that is afected. But now I have a job with 12000 names and it's a lot of job to do with this system. I need something like a script that fixes automatically. Can you understand me?
Sorry for my english, I don't use usally.
Thanks a lot.
Your English is a lot better than my Spanish.
THis problem was raised her a year or two ago, and someone, perhaps Harbs, wrote a script to adjust the font size to fit the frame for someone who was doing name tags -- a project that seems quite similar to what you are doing. I did a search and got lucky. Here's the link to the scripts: http://in-tools.com/downloads/indesign/scripts/FitTextToFrame.zip
And here's the other discussion: http://forums.adobe.com/message/2603447