You can certainly develop this, but there are many programs out there which can do this for you.

I use a program called Automation Anywhere http://www.tethyssolutions.com/automation-software.htm...

See sendkey command. Depending on what you need it for, it may be easier to use one of 3rd parth macro programs. I use Workspace Macro Pro, http://www.tethyssolutions.com/macro-automation.htm
There...