I am using Flexi 8.1 so it might be a little different, but here goes.
Setup your layout how you want it, where the barcode will go, place the number code there with the text tool.
With the select tool, select the number, then click Text/Barcode/then select Barcode 39 or extended.
You can change all your barcode settings in design central, on the last tab you can uncheck show titles to keep from showing the number.
You can then use auto serialize if each barcode is supposed to be a different number. Just remember to select the logo and barcode, just select the number entered for the text to be replaced.