There has to be an easier way...

I have a spreadsheet which lists about 12000 clients, each associated with one of approximately 100 different codes. There is a separate worksheet which then has the summaries for each code.

Each month I have to list all the clients relating to each code and the summary in a separate workbook.

At the moment, I'm using the filter function to select the code (which selects varying numbers of multiple rows). I then select the appropriate area to copy and paste this into a new workbook - can't copy the whole sheet otherwise it creates a much larger file.
Next, I select the same code from the summary sheet (using the filter function) and copy and paste this into a second worksheet in the new workbook (different column headings from the first worksheet).
Then save, using the code as the file name, and close.

I then select the next code down and start again!

I have to repeat this process around 100 times selecting the next code using the filters, copying and pasting, etc...

Is there a better way to do this?!

Thank you for any advice xx