You can add Text in Chart objects on the Presentation tab and add your expression as contents. In some gauges you can also your the chart title. You can enter an expression on the General tab of use the label of the expression.
Thanks for that, but the problem is I have different companys who change depending on filtering, so I can't add any text fields, becuse I don't know which companys will be shown (and in which direction...)
But I used your answer for a tachometer chart with only one dimension.