It seems like there could be one of three different scenarios here:
1. Your formatted report has the same columns as your existing Tableau worksheet.
2. Your formatted report has one or more columns that match, and the rest is different from your Tableau worksheet.
3. Your formatted report is completely different than the Tableau worksheet, and would be used to make different visualizations to add to a single dashboard composed of different data extracts.
What might help answer your question is depending on how similar or different your two data sets are. For example, I'm always adding additional data to my existing worksheet by right clicking on my data source, hovering over Extract, then clicking on Add data from file. This is different than say, #2 above where there would have to be some relationships between the two data sets to use both.
Since my worksheet and the 'report' have the same columns it simply gets sucked right up into my existing data set. If it were even slightly different, this wouldn't work without some prep work.
Thanks for your reply Jon.
Yes, I have one column that matches, and others are different. Since the columns are not matching, I guess some work is required to extract the data.