Prior to v8.0 there were separate Search and Replace Variable and Search and Replace Clipboard actions and the results always went back to the source variable or clipboard.
You can search for:
Select the source to search using the Search pop-up.
Select the kind of search to run, from the using pop-up. Then enter the text to search for in the text area.
Enter what to replace the found text with in the and replace with text area. Use the arrow at the right of the text area to select variables, clipboards and other tokens to enter in the text area.
For regular expressions, the replacement can refer to capture groups using either
\1 notation (eg
%Calculate%CHARACTERS(\1)% would be the count of characters in the first capture match (v8+)), or named capture groups (using
(?<name>...) with the notation
Select where you want the result to be saved (back to the source, or to some other variable or clipboard or file).
Using the action (gear) ⚙ menu, you can select (v10.0+) to replace all, or only the first or last match.
Search for: (.+) (.+) Replace with: $2 $1
Which results in: