Synonyms for With regard to:

adj.

concerning (adjective)
regarding.
regarding (adjective)
in relation to.

n.

with regard to (noun)
with reference to, in regard to, in relation to, regarding, with respect to, concerning, related, as to, vis-a-vis, related to.

prep.

concerning (preposition)
with reference to, regarding, in regard to.
for (preposition)
concerning.
toward/towards (preposition)
as to, with respect to.

Other synonyms:

as to
as to.
regarding
regarding.