Query different regex strings based with varying number of words

I want to be able to get a target filename from a string list with Regex, but with query that doesn't exactly match the files. The files:

• I have a few thousand files. I don't mind about query speed


• can have any case


• could have space, underscores, dashes or dots to break up words


• if the file uses "-" to break up the document name from it's source, just ignore the source (anything before the "-").


• if the exact terms are contained in a file that has other text in it, disregard this file (like FileList[0] in the example below)

As I will be doing many of these in my java application, I wanted to create a Java function that could handle varying sized input and filename strings.

Example:

Query = "microfluidic systems"

FileList[] = {
    "The.Fabrication.of.microfluidic.systems.in.PDMS.pdf",
    "IEEE - microfluidic systems.pdf",
    "microfluidic systems.pdf",
    "Self-Assembled Electrical Contact to Nanoparticles.pdf",
    "IEEE - Gallium Alloy as Lubricant_for_High_Current - Density Brushes.pdf",
    "Liquid Metal Marbles.pdf"
}

Here the second and third file should match the query.

Is this too difficult to do with regex? Or is it just that I will have to create case statements for each regex per the amount of words that are being used in my queries?

EDIT From QPaysTaxes's answer.

    String yourText = "microfluidic systems";
    String fileName = "sometext microfluidic systems.pdf";

    String search = yourText.replace(" ", "[\\s_.-]+").toLowerCase();
    Pattern pattern = Pattern.compile("\\s*" + search + "\\..+$");
    Matcher matcher = pattern.matcher(fileName.toLowerCase());
    if (matcher.find())
    {
        System.out.println(matcher.group());
    }

Prints the result:

 microfluidic systems.pdf

I think I might be missing something?