When build variables contain commas the command line generated by the plugin is malformed and results in the following error

MSBUILD : error MSB1006: Property is not valid.
Switch: John (US)

A sample of the full command line currently being generated is as follows:
cmd.exe /C C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe /p:Configuration=DEBUG '/P:GERRIT_PATCHSET_UPLOADER=\"Doe, John (US)\" <John.Doe@test.test>' /P:GERRIT_CHANGE_URL=http://test.url/58 /P:GERRIT_CHANGE_ID=I6455a12a4b64554c4bb580523f47033ec6b79c83 /P:GERRIT_CHANGE_NUMBER=58 "/P:GERRIT_PATCHSET_UPLOADER_NAME=Doe, John (US)" "/P:GERRIT_CHANGE_SUBJECT=Test Message" /P:GERRIT_PATCHSET_UPLOADER_EMAIL=John.Doe@test.test /P:GERRIT_BRANCH=master /P:GERRIT_REFSPEC=refs/changes/58/58/1 /P:GERRIT_PATCHSET_NUMBER=1 "/P:GERRIT_CHANGE_OWNER_NAME=Doe, John (US)" /P:GERRIT_PATCHSET_REVISION=6455a12a4b64554c4bb580523f47033ec6b79c83 /P:GERRIT_PROJECT=enterprise/profilesvc '/P:GERRIT_CHANGE_OWNER=\"Doe, John (US)\" <John.Doe@test.test>' /P:GERRIT_CHANGE_OWNER_EMAIL=John.Doe@test.test ProfileServices.sln && exit %%ERRORLEVEL%%