You can export your first report as EXCEL DATA ONLY (providing your alignment of columns is OK)
Then, save this file on a network drive or Local drive.
you can then create a new connection within crystal reports, and instead of using a database as your datasource, use the ACESS/EXCEL option and use your excel file as your datasource.
Just make sure this file always stays in the same place and it will be fine.
You can also add rows into this file as you would a normal table.
Im guessing this is what you mean.
If not, and you want 1 report to be the source data for another report AT THE SAME TIME as running the reports (dynamic), then you need to look into subreports.