Adding new city tiles to an already existing map . . . Can it be done?

[forevering]

I have been playing on a map for some time now.  it is 15x15 large city tiles.  There is some terrain on the left hand side of the map where I really would like to make a large city, but it is too close to the edge of the map.  i would like to add a tile or two on that side of the map.  I thought, hey, why don't i try to enlarge the image. 

things I tried

1. just enlarging the image added the tiles to the right side of the map . . . cool, but unneccesary. 

2. When I tried to enlarge the canvas size and keep the image to the center right, so the pixels were added on the left, it did this weird thing where a bunch of cities disappeared. 

3. next i tried, opening the region with the config acquired in step 2 in terraformer.  this caused the new tiles to appear on the right again.  I am tired of experimenting and was wondering if any of you could help me out?  I see people adding tiles to their regions all the time . . . how do you do it!?

[catty]

I create a new blank region and then using the built in SC4 import program I move my cities across into the new region, SimCity swops over the tiles between the old and new city so when you are finished the old tiles are in the new region and the new tiles are in the old region

as long as you get everything back in the right place your cities shouldn't even notice they have been moved

[forevering]

thanks, I decided to just do that . . . it's going to take forever since . . . i started with a 15x15 sized region.  still looking for a better way to do this . . .