Working with a .PO file in memoQ
Context:memoQ's native PO filter
To translate PO files using memoQ, we recommend that you either use Rainbow from the Okapi framework (open source software) available here:
Or if you're after something slightly older but maybe simpler for some, there is a PO to XLIFF converter (and back) here:
Both tools will allow you to convert the .PO files to .XLIFF for translation in memoQ. Once translated, you can convert back to the original PO format.
Other solutions do exist, like Preptags, a 3rd party tagger, which would allow you to prepare your PO files for translation into memoQ, but that would require more advanced knowledge than the first 2 I listed here.
Comment: Please also note that newer versions of memoQ offer a regex text import filter that allows you to import directly monolingual .PO files.