diff --git a/mRemoteNGTests/Tools/ExternalToolsArgumentParserTests.cs b/mRemoteNGTests/Tools/ExternalToolsArgumentParserTests.cs
new file mode 100644
index 000000000..016937d91
--- /dev/null
+++ b/mRemoteNGTests/Tools/ExternalToolsArgumentParserTests.cs
@@ -0,0 +1,84 @@
+using mRemoteNG.Connection;
+using mRemoteNG.Tools;
+using NUnit.Framework;
+
+
+namespace mRemoteNGTests.Tools
+{
+    public class ExternalToolsArgumentParserTests
+    {
+        private ExternalToolArgumentParser _argumentParser;
+        private const string TestString = @"()%!^abc123*<>&|""'\";
+        private const string StringAfterMetacharacterEscaping = @"^(^)^%^!^^abc123*^<^>^&^|^""'\";
+        private const string StringAfterAllEscaping = @"^(^)^%^!^^abc123*^<^>^&^|\^""'\";
+        private const string StringAfterNoEscaping = TestString;
+        private const int Port = 9933;
+        private const string PortAsString = "9933";
+
+
+        [OneTimeSetUp]
+        public void Setup()
+        {
+            var connectionInfo = new ConnectionInfo
+            {
+                Name = TestString,
+                Hostname = TestString,
+                Port = Port,
+                Username = TestString,
+                Password = TestString,
+                Domain = TestString,
+                Description = TestString,
+                MacAddress = TestString,
+                UserField = TestString
+            };
+            _argumentParser = new ExternalToolArgumentParser(connectionInfo);
+        }
+
+        [OneTimeTearDown]
+        public void Teardown()
+        {
+            _argumentParser = null;
+        }
+
+
+        [TestCase("%NAME%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-NAME%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!NAME%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%HOSTNAME%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-HOSTNAME%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!HOSTNAME%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%PORT%", ExpectedResult = PortAsString)]
+        [TestCase("%-PORT%", ExpectedResult = PortAsString)]
+        [TestCase("%!PORT%", ExpectedResult = PortAsString)]
+
+        [TestCase("%USERNAME%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-USERNAME%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!USERNAME%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%PASSWORD%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-PASSWORD%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!PASSWORD%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%DOMAIN%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-DOMAIN%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!DOMAIN%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%DESCRIPTION%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-DESCRIPTION%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!DESCRIPTION%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%MACADDRESS%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-MACADDRESS%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!MACADDRESS%", ExpectedResult = StringAfterNoEscaping)]
+
+        [TestCase("%USERFIELD%", ExpectedResult = StringAfterAllEscaping)]
+        [TestCase("%-USERFIELD%", ExpectedResult = StringAfterMetacharacterEscaping)]
+        [TestCase("%!USERFIELD%", ExpectedResult = StringAfterNoEscaping)]
+        public string ParserTest(string argumentString)
+        {
+            return _argumentParser.ParseArguments(argumentString);
+        }
+    }
+}
\ No newline at end of file
diff --git a/mRemoteNGTests/mRemoteNGTests.csproj b/mRemoteNGTests/mRemoteNGTests.csproj
index 8a07545b9..6252a216d 100644
--- a/mRemoteNGTests/mRemoteNGTests.csproj
+++ b/mRemoteNGTests/mRemoteNGTests.csproj
@@ -114,6 +114,7 @@
     <Compile Include="Config\Serializers\RemoteDesktopConnectionDeserializerTests.cs" />
     <Compile Include="Config\Serializers\RemoteDesktopConnectionManagerDeserializerTests.cs" />
     <Compile Include="Connection\AbstractConnectionInfoDataTests.cs" />
+    <Compile Include="Tools\ExternalToolsArgumentParserTests.cs" />
     <Compile Include="Tree\ConnectionTreeDragAndDropHandlerTests.cs" />
     <Compile Include="Tree\ConnectionTreeModelTests.cs" />
     <Compile Include="Connection\ConnectionInfoInheritanceTests.cs" />