stacked column/bar chart w/ monthly data + single line of daily data

I could use some help creating a MONTHLY stacked bar/column chart (with 3 series of data) with a DAILY line chart overlaid (one series of data). For example, in the bar/column chart portion, I want to compare the monthly sales of my company with two other companies (three different colored bars for each monthly period). This is easy enough to do. But then I want to add another series of daily data (different Y axis - different number formatting & range) on top of the sets of bars/columns. This I cannot figure out how to do. The biggest snag that I run into is the X-axis data not matching (monthly dates versus daily dates - even though both data ranges are over the same time period, of course).

Any help would be much appreciated!