No!
A hopback works on the principle of near boiling wort disolving a whole range of hop compounds and is reliant uon the heat doing this. The heat also starts to alter these compounds. Dry hopping will not dissolve the same range and will not alter them.
A big whack of hops at flame out, followed by rapid chilling will have a similar effect as a hopback (but not identical). Some brewers have tried hopbacks and gone back to late hopping other swear by them.
Just keep in mind that hopbacks were not developed as means to add extra flavour, this is just a by-product. Their original intention was to act as a filter bed for wort being cast out. However over time some brewers have adopted them for the primary process of adding hop flavour/aroma.
Cheers
MAH