Regan had nothing to do with Resolution 242 and Resolutions 242 never stated that Israel has to withdraw from ALL territories, and any exchange of territory would only happen when a comprehensive peace agreement was signed, and Israel gets all the security guarantees it demands,
something that Palestinians are not willing to provide.

Lord Caradon, the chief author of the resolution wrote: "We didn't say there should be a withdrawal to the '67 line; we did not put the 'the' in, we did not say all the territories, deliberately.. We all knew - that the boundaries of '67 were not drawn as permanent frontiers, they were a cease-fire line of a couple of decades earlier... We did not say that the '67 boundaries must be forever; it would be insanity." 

Secretary of State Madeleine Albright told the U.N. Security CounciL:We simply do not support the description of the territories occupied by Israel in 1967 as 'Occupied Palestinian Territory'.