Relative Path is actually the short one(less complex) while absolute is the full path.
With alias you will still be able to use the short path.
Create a file index.html and a style.css with respective contents.
index.html file should contain the following line in the head tag:
Code
<link rel="stylesheet" href="style.css">
Copy it into some folder. Then from Ampps Enduser Panel create an Alias with any name and with the path of the folder where these two files are located.