How to install a .deb file (Steam) to a partition of my choice (data partition)

I am using xubuntu and have a separate /home directory plus a 'data' directory which is much larger than /home and on the same drive. The 'data' partition is formatted NTFS to allow Windows 10 access.

I believe a default install of a .deb file installs to your /home folder.

I want to install a Steam .deb package (from the Steam web site), which is a minimum of 21GB to the 'data' directory and am unsure how to achieve this.

'Googling' makes me even more unsure! Can anyone assist?