hy retro
i m next to sure that you can do that! ... but be aware that sound module often handle midi dumps just differently! ... so i ain't sure how the dx7 handles that! you'll need to check it up in your manual! ... but its surely not done in the global page! you'll do it from your sequencer/main page!
i can tell you what i do on my virus! uploading sounds/patches/os: i just load them first on my hd on the 4k via usb! then load it into its memory (which gets emptied before): take it into sequence1/track1 set its output to ch1 (which controls my virus), loop off, hit play and the new os, patch ... is sent to the virus! the good thing is you always can backup synth patches/os right on your hd on the 4k! so if you should ever need a patch, os again ... you know its there! ... and os uploades can take quite a while! so don't worry while your beauties ar workin, they'll do it, lay back and take it easy! ... single patches are uploaded quite quickly though!
as far as dumpin from the virus to the mpc! the virus has several options: dump single patch, whole bank, arrangement, multi buffer, ... (the dx7 will probably have other options, terminology but i m quite sure that there are distinguished options as well)! i most likely dump arrangements which are basically (the 16 sounds) i use on the virus for a given song, or single patches if i want to use 1 sound (on one channel) in different ways! ... and i always dump them on 1 seq/track! ... and in different versions! so arrangement one is saved on seq 128, track 1, arrangement 2 on seq 128 aswell and track 2, ...! the single ones: patch 1 on seq 127, track 1, patch 2 on seq 127, track 2, .... and if you do a 2nd dump of an arrangement, patch mute the first one cause it might cause trouble when sended back to your module while the other one is uploaded on the same midi channel! ... even though disconnecting irrelevant midi cables there might be the savest way!
hope that helps! ... good luck! ... and nice synth bro!
alto