Outlook Subject Macro

I am new to VBA and VB macro writing and was wondering if someone out there could help me out. I am looking for a macro that when you press a mapped keystroke (i.e. Alt+z) pre-specified text will pop up in the subject line.

I figured out how to do it in word:
Sub Macro3()
Selection.TypeText Text:="Text Here"
End Sub

This does not work in outlook, however, unless you change the outlook editor to "Use Microsoft Word for email editor" instead of keeping it HTML.
Please help!!