Then, what you need is a custom font with a 'small caps' feature.
A few (free) ones that I know:
- Alegreya SC
- Alegreya Sans SC
- Vollkorn SC
- Ysabeau SC
They all include the three European scripts (Latin, Cyrillic and Greek).
But be aware that custom fonts used in virtual tags are taken into account in the main panel,
not in the thumbnail browser or the column browser.