Need to pare down huge data file for plotting

We have a piece of test equipment, home grown, that is controlled by a VB program. In a few minutes, it gathers a lot of information from different sensors and inputs, and exports them to an XL workbook that ends up consisting of a dozen worksheets.

One worksheet alone has 18 columns and about 53,000 rows. Needless to say, it takes a long while to plot this data.

The data is necessary as it is, but the plot does not need to have that fine of a resolution; instead, it would be just fine if we plotted every 25th row. So instead of 53K+ rows, we could have just over 2100 rows.

I need a macro that would copy every 25th row and paste it on another worksheet, and then we could more effciently plot this new, abbreviated data. It probably would be better if this 'other' worksheet were in a different workbook as well.

I would attach the workbook with the data, but it is over 27MB!

Thanks for your help.

Alex