Create simple excel macro requiring less than 4 hours of work

I need a macro to perform the following Look at range A1:A500. Numbers in these cells could be either 4, 6, 10 or 11 digits. If in a cell in this range has the same 5th leftmost digit 4th leftmost digit and 3rd leftmost digit and the same 2nd leftmost digit then take the 1st leftmost digit and place it into a matrix. Place all the numbers in the matrix in a new column in the following format: [] see example below: 4000 400[0235789] 4002 400[0235789] 4003 400[0235789] 4005 400[0235789] 4007 400[0235789] 4008 400[0235789] 4009 400[0235789] Now I don't want a bunch of repeats so if cell B1=B2 then leave cell C3 blank if B1 not equal B2 then move value to C3. If the matrix has a total of 10 digits then represent that value as "400." where "X" replaces the [] format. If in column C there is a repeat of the 5th 4th 3rd and 2nd leftmost digit and there is a "X" in the 1st leftmost digit then place the 2nd leftmost digit into a new matrix. See example below 4010 4011 ... (numbers continue in order) 4019 4020 ... (numbers continue in order) 4029 4030 4032 - 4031 is missing. result is 40[12]X Ok then place all the results in a nice neat new consecutive column