This script seems to trivial to me. To upload upload multiple dists, you could simply run
dput ppa:<user>/<ppa> ${PROGRAM}_${VERSION}~${dist1}_source.changes ${PROGRAM}_${VERSION}~${dist2}_source.changes ${PROGRAM}_${VERSION}~${dist3}_source.changes
and so on.
This script seems to trivial to me. To upload upload multiple dists, you could simply run
dput ppa:<user>/<ppa> ${PROGRAM} _${VERSION} ~${dist1} _source. changes ${PROGRAM} _${VERSION} ~${dist2} _source. changes ${PROGRAM} _${VERSION} ~${dist3} _source. changes
and so on.