All you have to do is instead of using the cell range (A3), just use the cell name into the into the Cell range node.
The attached image show a bit of code when I had to this to write to a named cell. This code had to create all the references first, so if you already have a reference to your sheet open, you'd probably just need the '_Worksheet>Range" node with the name specified.
Ed

Ed Dickens - Certified LabVIEW Architect
Lockheed Martin Space
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