Conditional format (modeling) of number

Hi everyone.

In a report I've defined a measure as follows:

Measure = IF('TabFlag'[Flag]="Abs"; [KPI Absolute]; [KPI Percentage])

And I've associated a slicer to the flag, which allows the user to choose between KPI Absolute and KPI Percentage (which are two different measures).

I want to show the measure in a bar chart, but the problem is that it's not possibile to me to give the right formatting of the number: I would like that the value of Measure is showed as a whole number if the absolute form is selected, and that the same Measure is showed as a percentage if the other option is preferred.

I've tried using the FORMAT DAX function, but it return a string, which cannot be represented in the bar chart, so it does not suit at all.

Thanks.