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Unfortunately no. You cannot apply condition rules that can be specific only to a cell in the Matrix table.
Usually the workaround used is by using a separate Textbox field (outside the matrix table) or use another Matrix table with only single column (just for the purpose of having a separate textboxes)
You may want to try using Spreadsheet Widget as an alternative to Matrix table.
The spreadsheet widget will allow you to have control on the cell contents. You can assign a default value to the specific cell address.
Hope this help. Let us know if you need further assistance.