As it turns out, concantenating values is not currently supported in the reporting grammar.
One option you could use would be to create a parameter and pass in the complete package name when running your report. For example, add the following section to the end of your report template:
$info
$description "Please enter the package name you would like to report on."
$param $$pkgname
$endinfo
You would then edit your template to something like this:
$repeatPackages where Name = $$pkgname
This won't grant you the ability to report on multiple packages within a single report, but would have the same effect on a package by package basis.