When setting up perfect match, you first need a regular expression to match against if you are not using exact file name matching. Filename regular expression replace template takes the values identified by the first regular expression and uses them to create the regular expression that is applied to old (translated and reviewed) file names to find matching file names. The values identified by the first regular expression are represented by variables in this second regular expression.
In this example, we have the old file format that was used
Test File - 01ABCD2345QQ.xml
But now the filename formatting has been changed to
01ABCD2345QQ Test File.xml
Because of this, you will not see a match with your older translated files using filename matching.
To fix this, you will need to create a regular expression that matches the new format:
([0-9]{2}[A-Z]{4,6}[0-9]{4}[A-Z]{2})(.*)\.xml
The file being translated has a product code number at the beginning of the file, a name after the code number and a file ending with .xml
This expression can be split into the following groups
Group 1: ([0-9]{2}[A-Z]{4,6}[0-9]{4}[A-Z]{2}) - This defines the product code "01ABCD2345QQ"
Group 2: (.*) - this defines the product name " Test File"
As the older files had the product code number at the end of the file, using a Filename regular expression replace template, you can define how the older files can be found by moving the pattern to fit the already translated files:
$2$1\.xml
Where $1 represents the first grouping of the Regular Expression, and $2 the second.