I'm not sure I follow what you're up to but here is a suggestion...

You can change the number of beats in a measure. Right click on the measure, choose Bar Settings... and change # beats this bar. If you are in 4 and change it to 2, it will remain in 2 for the rest of the song. Be sure to change it back if desired.

If this is not what you want, maybe you want a Tag ending.

Rachael