PressKeys

I am new to SilkTest.  I am using .Net to record keystrokes from BlueZone mainframe emulator.  I am trying to highlight some characters on the mainframe screen and do a copy and paste using the following commands:

.PressKeys("<Shift>")

.TypeKeys("<Right><Right><Right><Right><Right><Right>")

.ReleaseKeys("<Shift>")

.TypeKeys("<Left Ctrl+c>")

.TypeKeys("<Left Ctrl+v>")

During playback, it is not recognizing the PressKeys command and therefore only moving the cursor to the right with the TypeKeys.  I'm not sure if the copy/paste works because I have not captured the highlighted characters.  I also tried using the mouse control (rather than keystrokes) with the same results.  Any suggestions?