Case conversion in regexp replace

I'd like to normalize the key indication for classical tracks. In the Replace dialog with Regular expression enabled, I'm trying to use the \l \L case conversion syntax which works in e.g. Notepad++ or BBEdit:

Find: In ([A-Ga-g]) minor
Replace: in \l\1
Example: Fugue In G minor BWV578
Expected output: Fugue in g BWV578

Is there a way to achieve this in Kid3?