As far as I know, there are two ways to increase the frame by 1 (which is what you need to do):
In areas with grass/in caves/on water/whatever: Take 1 step. Turning counts as a step. Turning and stepping counts as 2 steps (ie. facing left, pressing up, taking one step up).
In areas without grass (basically, a route where you can't encounter anything): Take 128 steps with 1 Pokémon in your party. Turns don't count.
(Please feel free to correct me if any of this is incorrect.)
Neither of these are going to work for picking up an egg, so you'll need to consider your roamers (Cresselia and Mespirit). Are you in Platinum? If you are, you can either release one/another, OR find one that's already released and faint it. Beating the Elite Four will respawn them. If you've already beaten both, beat the Elite Four and release one. If you've already caught both, then unfortunately, you're out of luck. Find a different spread on a frame that's odd.
Your only other option is to get to frame 7 like you were before, and then wait for one NPC to move. This is incredibly tricky and will likely require insane luck and/or multiple retries. I'd go for the odd numbered frame if manipulating the roamers is out.
Incidentally, breeding eggs is like falling off a log in HG/SS, and you can check/advance your frame a lot quicker too, and with greater precision. Plus, there's only one NPC on the breeding route, so if packing up and moving to a newer game is an option, you should really consider it.
~Uiru