Anyone aware on how to insert the data into excel file from a specific line number (in excel sheet)?

Simplest thing whould be to use the glob pattern to filter the files you want the directory browser to collect.

Link to Directory Browser documentation:
Directory Browser

Other thing you could try is to add a Gate snap after the filter on your current design. The gate snap will continue even if you don’t have anything on input.

Be careful though, if your files volume increases over time the gate snap can be dangerous since it puts everything that it’s received on input into an array.