Avoid columns with no header in Matrix table

Hi All, 

I have two data tables connected with unique IDs.

Table one inclues all users. Table two has the user subsciptions ( not all users have subscriptions , but who have, have only one)

I'd like to create a matrix table to show in the columns the type of subcriptions and to display 'no subscription' for the ones who have none instead of having a blank column header.

Is there any option to add a name to the blank column without merging the two queries?

Thanks in advance, 

Eszter