Force Specific Variations
All you need to do is grab from your Convert Experiences account the IDs of both your experiment and variation that you want to force. You can do that as explained in the following article
After you have the two IDs handy you can build the query variable that needs to be added to the experiment URL:
_conv_eforce=[experiment_id].[variation_id] where [experiment_id] and [variation_id] will be replaced with actual values.
Example: http://www.mysite.com/test-page.html?_conv_eforce=123.678 where 123 is the experiment ID and 678 is the variation ID;
To get the variation id, can be easily collected by doing a Live Preview of the variation. You can do this by going to the report section and previewing the selected variation.
You will see the variation id at the end of the URL of the live preview.
The variation's ID is the value of the query variable convert_v (the number after "convert_v=" in the URL )