How can I replace, say, 250 out of 1000 words in Microsoft Word?
For example, 'happy' is written about 1000 times in my document. I want to replace only 250 of them with the word 'joy'.
So is there a function or way to do that at once in Microsoft Word?
The quickest way is to do a "Find" (Ctrl+F) and cycle through each individual instance and select replace when you wish to replace the instance with "Joy".
This solution will probably be more programming intensive than what you are looking for but I'll put in out there is case it is of use to someone. MS Word just stores a document as a zip file with a .docx extension. You can unzip it with standard utilities. The zip file contains a number of xml files as well as other files that hold formatting information. The body of the document is stored in a file called document.xml. Since this is a text file it is possible to write an application to do a search and replace on only a specific number of matches and then re-zip the file and rename it with a .docx extension. As was mentioned earlier this could also be also be done with one of the Visual Basic/C languages using VSTO but there may be more of a learning curve if you haven't used it before.
Here is a method directly in Word for replacing every 3rd, then every 5th occurrence of "happy" with "joy'. After you record one macro (to make an average of 25% swaps), you run a second macro once that runs the first one to document end:
Click "Find Next". Click "Find Next". Click "Find Next". Click "Find Next". Click "Find Next". Replace "happy" with "joy". Stop Recording.
Record MacroJoy2, which runs MacroJoy1 125 times. Number can be higher. Stop recording.
Run MacroJoy2!
It's a bit of a pain, but as far as I know there is no such function native to MS Word. Besides that, you'll probably be best off using CTRL+F and reviewing each case individually for context, rhythm, etc. before making changes -- indiscriminate machine replacement will probably make more problems than it solves.
Yeah, like other people are saying, making a VBA Macro is the way to go:
Something like using the Find function, then randomly, with the RND function, going some number of spaces ahead, and then replacing the selection with the word you want.
Only manually, or by subjecting your Word document to a programming language… which for any single instance will almost certainly be at least as difficult.
To the extent you can re-use it the idea becomes more efficient, though no more easy.
Word itself has no conception of how to replace X out of Y words.
Not random, but no special tools required. To replace every fourth occurrence (case sensitive):
Find and Replace > Replace
Use wildcards = checked
Find: (<happy>*)(<happy>*)(<happy>*)<happy>
Replace: \1\2\3joy
Replace All
With (some) case insensitivity:
Find and Replace > Replace
Use wildcards = checked
Find: (<[Hh]appy>*)(<[Hh]appy>*)(<[Hh]appy>*)<[Hh]appy>
Replace: \1\2\3JOY
Replace All
Match case = checked
Find: JOY
Replace: (joy|Joy, as required)
(The repeat function ({3}, {1,3}) doesn't like wildcards (*), so multifind statements like this have to be manually created.)
This can be made pseudorandom by replacing multiple times and with different occurrences (e.g. every 7th, then every 5th). The Find and Replace input boxes are limited to 256 characters, so there's only so many that can be done in one go (19 in this case). But any more than every 7th results in the error 'The Find What text contains a Pattern Match expression which is too complex':
(<[Hh]appy>*)(<[Hh]appy>*)(<[Hh]appy>*)(<[Hh]appy>*)(<[Hh]appy>*)(<[Hh]appy>*)<[Hh]appy>\1\2\3\4\5\6JOY