-snip-
i will try creating the alias. so it will be like a modified shortcut correct?
Yes
When u say behind it what do you mean?
Well Mac is not my cup of tea. I usually can do what I want with it when Im in front of it, but its more a trial and error
With Win a shortcut would be like this (note: random picture from the web)
But since most of your wallets would be installed in Program Files which has a space there are quotationmarks around the path.
"C:\Program Files\Bitcoin\bitcoin-qt.exe"
So for bitcoin-qt and Win (at least 7) youd have to change this to:
"C:\Program Files\Bitcoin\bitcoin-qt.exe" -datadir=d:\bitcoin
behind the normal path and file and after the ending quotationmark.
With Mac this should work similarly, only that your path would be different and that mac is not using .exe files.