Rearranging a Tikun for columns with different width and number of lines

I have a tikun for megillat esther of 48 lines per column where the last two columns are narrower then the first 8 columns and I need to convert those two columns to normal width columns. The last column of writing does not need to end at the bottom of the column (and probably shouldn't considering that the letters would have to be radically stretched to keep the columns at 48 lines when widened). Do I just take the average number of letters (or yud spaces) on the normal width columns and estimate where to mark off the end of a line by counting letters and marking off the end of the column after the normal amount of letters on a normal column (adjusting, of course, to make sure that words aren't cut in half)? Meaning, for example, if there were about 30 letters per line on a normal width column, I would count 30 letters on the narrower columns and then adjust by as small a margin a possible to make sure that a word wasn't cut into pieces (and that the parshiyot still work out) and then count that as one line, and continue to do that until I got to the end of the tikun, with an average of 30 letters per line on every line. Is there maybe an available software that makes this easier?