Insert "_" after every word in file name

I decided to fix the file names on my external HDD. I would like to change the cas of all files and to put symbol "_" (underscore) between every word? Is it possible and if it is how to perform it?

Please note that all file names have different number's of letters.

Thanks

Cheers

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Reply to #1:
How are the words currently separated?

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Reply to #2:

Normal with space between every word.

Example:
manual call point installation manual
fire control panel programming manual

Shoul look like this:
manual_call_point_installation_manual
fire_control_panel_programming_manual

Thanks

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Reply to #3:
What you can do is to replace all spaces with _. You can do that by using the Replace Method and configure it like this:

Text to be replaced: "here you should type a space"
Replace it with: _
Use regular expressions: Unchecked

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Reply to #4:

Great suggestion!

I already try it and it works perfect!

Thanks

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