match string pattern by certain characters but exclude combinations of those characters

Question

I have the following sample string:

 '-Dparam="x" -f hello-world.txt bye1.txt foo_bar.txt -Dparam2="y"'

I am trying to use RegEx (PowerShell, .NET flavor) to extract the filenames hello-world.txt, bye1.txt, and foo_bar.txt.

The real use case could have any number of -D parameters, and the -f <filenames> argument could appear in any position between these other parameters. I can't easily use something like split to extract it as the delimiter positioning could change, so I thought RegEx might be a good proposition here.

My attempt is something like this in PowerShell (can be opened on any Windows system and copy pasted into it):

 '-Dparam="x" -f hello-world.txt bye1.txt foo_bar.txt -Dparam2="y"' -replace '^.* -f ([a-zA-Z0-9_.\s-]+).*$','$1'

Desired output:

 hello-world.txt bye1.txt foo_bar.txt

My problem is that I either only take hello-world.txt, or I get hello-world.txt all the way to the end of the string or next = symbol (as in the example above).

I am having trouble expressing that \s is allowed, since I need to capture multiple space-delimited filenames, but that the combination of \s-[a-zA-Z] is not allowed, as that indicates the start of the next argument.