hi

i am trying to find a solution to this problem.I have looked at various post but can seem to put anything together to get the outcome i need
PHP Code: 
A1 model   B1  poduct
A2 pp2      B2  lop2
A3 pp2      B3  lop4
A4 pp3      B4  lop5
A5 pp3      B5  lop6
A6 pp3      B6  lop7 
A1 contains multiple similar model and b1 contains products what assosiate to that model, i want to print out in Coloumn C products which have same model number in Row A .separated by a coma.For example like this

PHP Code: 
A1 model   B1 product           C1
A2 pp2      B2  lop2               C2   lop2,lop4
A3 pp2      B3  lop4               C3 (stays empty as result is copied into C2)
A4 pp3      B4  lop5               C4 lop5,lop6.lop7
A5 pp3      B5  lop6               C5 (stays empty as result is copied into C4)
A6 pp3      B6  lop7               C6 (stays empty as result is copied into C4) 
The excel file has over 12000 rows and doing it by hand is taking way too long and the list changes daily.

Any help would be appreciated.

kind regards

Nafri