Subtotaling columns of numbers using autofiltered text evaluations in adjacent columns

Hi everyone,

First I'll apologize. I don't know VBA. I make my way pretty well through most of the common functions I need like SUMIF and SUBTOTAL. This one has me perplexed. In the attached example columns M through U contain financial sales figures. Columns A through J contain data representing different regions, branch offices, personnel, etc for which I use autofilters to drill down. Notice also that column K shows what we internally refer to as Planning Segments.

My dilemma is this:

I want to create a header area at the top of the page which will will subtotal the columns of financial data associated with a given Planning Segment as I use the auto filter to make selections in columns A through J

As an example, if I filter column J to pick a different Distributor Sales Person, I would want the header area (shown in the example with all the Planning Segment names as placeholders) to update based on the new autofilter setting.

This is a partial data set. The full set of data is nearly 300,000 rows. I know I could create separate additional columns of data unique to each Planning Segment and then subtotal those....but then the file size grows even larger than the 27MB it already is.

Any suggestions?

Thanks!
RJ