I suggest making a bash alias.
Login with a non root account and open a terminal window
After you get the terminal window open, use vi to open ~/.bashrc
In vi, either look for the aliases or just go to the end of the file
Press the 'i' key (without quotes) to enter insert mode
Type the following into your .bashrc file
alias lampstart='/opt/lampp/lampp start'
Press ESCAPE to exit insert mode
Type the following to save the .bashrc file and quit vi
At the terminal, type the following command to reload your .bashrc file
lampstart in your terminal, and lamp should start. You could actually name the alias whatever you want, i just used the alias lampstart because it seemed logical.