I need to exclude files with the following pattern:
ProjectFoo.Data[0-9]{14}.lgp
How can I use RegEx for (Visual)SVN ignore list?
The subversion ignore list don't support regular expressions. They are implemented as glob/file patterns.
These patterns don't support the {14} repeat construct.
The pattern
ProjectFoo.Data[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9].lgp
should do what you ask, but I would recommend using something like ProjectFoo.Data[0-9]*.lgp as that would be 'good enough'.
As the file looks like an LLBLGen Pro project backup file, you can force llblgen pro to store backup files into a separate folder (See preferences: default backup folder), e.g. .\Backup. This way you can exclude that folder in svn and you're done :)
Some basic advice for how to use the other answers on this page with TortoiseSVN backed by VisualSVN Server. You can manually add an svn:ignore property to the folder. Bert's glob/file advice for the patterns works well there (I went with the "good enough" [0-9]* myself). More info here.
Navigate to the folder you want and right click | TortoiseSVN | Properties | New | Advanced. Choose a Property Name of svn:ignore and then enter your glob/file patterns on separate lines in the value box.