You can do that with css. First you need to add your own css stylesheet (check help.openerp.com/question/5783/how-to-add-a-custom-css/ on how to do that)

Then, inside your css, you can select your desired column with css attribute selector (www.w3.org/TR/selectors/#attribute-selectors) just like that:

[data-id="name"] {
    width: 200px;
}

Of course, you need to fine-grain your selections.