Try right clicking on the bar you want to start changing the beats on, click on bar settings in the box that comes up, then in the [# beats this bar] box put 2, then click OK. Put in your the 1 chord in the first box, then in the next bar put the 4 chord in the first box and the 5 chord in the second box. "You may have to put 4,5 in the first box and leave the second box blank to get the sound you want". In the next bar put in the 1 chord in the first box. Right click on the next bar and change the [# beats this bar] back to 4 and continue as you normally do. This will add bars and make the bars look off but the music should come out right.
I think this should do what you want to do. You can play around with the bar settings to get what you want.
You also may have to change the tempo on these bars to get what you want.