Concatenate

Hi,

I'm not even sure if this can be done...but...

In column 'A' i have a list of numbers and in column 'C' i also have a list of numbers. However the same number may appear in column 'A' numerous times (they will appear 1 above the other as i have sorted them) whilst the number in 'C' will vary even if 'A' is the same. What i basically need to do is some form of concatenate...where in column 'g', on the same row as a number in 'A' a concatenate formula is entered. This will concatenate all the variable in 'C' of the duplicated SKU in 'A'....but it will have to be in column 'g' where the number first appears in 'A'......

yes complicated....i have attached an example sheet....