Is it possible to convert text from a certain cell to RFC 3986 (http://url-encoder.org/) in a Google Spreadsheet?
C4 has the value
John Doe, then
D4 must be
Yes, you can create a custom function for that.
Click Tools → Script Editor. Select Create blank project.
In the script editor window, paste the following code:
Save the script (give it a name if prompted), and return to your spreadsheet.
Now, you may use the function as
I have created an example spreadsheet to demonstrate.