The "@" thing will be because Dosbox thinks you have an American keyboard by default. There's a DOS setting I can't remember now ("keybuk"?) that would switch it to UK keyboard mode.

Why not write a simple batch file and run that at the Dosbox prompt? It would set the PATH string, move to the relevant directory and then fire up the program you want to use. Call it a.bat, put it in the default directory and then all you need to do after starting Dosbox is to type "a" "return" and away you go. Any other DOS programs you want to use get b.bat, c.bat etc. You can also put the "keybuk" command in there too.