Sounds like you could use a macro program. I wish there were one.

 

This may not help, but you could(using Handcent) create a new Quick Text for the string you need, and I use Better cut for editing home screen icons, but it also lets you put a small icon on the home screen for direct dial or texting,

so:

Use Handcent or Chomp(not tried it on Chomp)

Create new Quick text

Get BetterCut (Sense has a widget for putting direct texts on the home screen but i find it takes up too much room) and create a direct text ico

This wont make it possible in one press, but it will reduce it considerably!!