Copy pivot table data to specfic cells in different workbook

I have dynamic pivot table (that is generated from a CSV file) that lists the amount of times a particular site was visited in a particular month. (I have attached a snapshot of the pivot table in the hope I get my meaning across).

In a seperate workbook I have a list of site numbers in Column A and would like to populate the number of times each site was visited Column C (April visits) Column D (May visits) Column E (June vists) etc...

I have used the following formula which seems to work:

=VLOOKUP(A3,'\\Network Path\[SiteReport.xls]visits per month'!$A$5:$B$71,2,FALSE)

As the pivot table is dynamic, new sites will appear in the pivot table, when they are visited for the first time, which are not listed in the other workbook, so some method need to be found to include them.

I would be very grateful if someone could explain how I can lookup the values provided in the pivot table and then, if they don't match to the correct site (because they are new in the pivot table and don't exist in the other workbook), create them in the new workbook and populate the month column with the correct amount of visits.

Many thanks