how to find out row in delete buffer for dw?

I have a datawindow dw_1.  I use following script to move all data from Primary buffer to Delete buffer.

dw_1.RowsMove(1, dw_1.RowCount(), Primary!, dw_1,1, Delete!)

Then I want to find out a row in Delete buffer like dw_1.Find(...).

How can I do it? If all datawindow functions can be applied for Delete buffer?