How to keep X amount of beginning characters

I've looked around the help section, but I can't find any reference to being able to keep a set amount of characters in the file name while removing the rest. For example if I have files prefixed with "FILE: xxx xx.nn Some Long File Name Here", (and assuming the naming convention has the same amount of characters in the beginning), how do I end up with file names such as "FILE: xxx xx.nn"?

It's the opposite of being able to remove X amount of characters "backwards".

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Reply to #1:
If you want to keep the first 15 characters I will recommend to use the NewName method and use this pattern:
<Substr:1:15>

I will replace the filename with the first 15 characters of the filename and leave the rest out.

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Reply to #2:
It would be great if this feature could be used to rename long filenames. I vainly tried.
Using filenames over 260 characters.

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