You'd have to use an adverbial phrase such as "in a lovely way", "in a lovely manner", or (depending on the particular context) a more specific adverbial phrase such as "with a lovely turn of phrase" (for how someone articulates a point). To make these phrases comparative, you can use lovelier or more lovely, and loveliest or most lovely.
The degree of emotional resonance of "lovely" depends on context, precise phrasing and (in the spoken language) tone.