Comparing columns and highlighting differences

Hi guys

First off! Thanks for an excellent forum. Been using it quite a bit during the last month and will continue to do so in the future.

My first post here is about comparing the contents of different columns in a sheet. There are two sets of data that needs to be compared.

The setup is as follows.

Every time a factory completes an order it is shipped to a warehouse. Everytime this happens they register the outgoing shipment using a date, reference number and an amount.

When the order is received at the warehouse they do a similar registration adding additional data as well.

And as stated above I would like to compare the reference numbers to see if they are present. If they match I should then look at the amount registered to each reference number.

If there are reference numbers present in either dataset my idea is to color the entire row red (or something like that).
If the reference number is present but the amount doesn't match this line should get a different color.

I have made a simple, not very good comparison macro, that writes directly to the sheet in a new column (not included in the current code).

But this is a cumbersome process and I would like to think that it could be done using arrays, the find function or something similar.

In the current code I have created two arrays containing the the information from the factory and the warehouse. Don't know if this is a step in the right direction or not but I'm hoping you guys could tell me

Kind regards
Michael