SSRS will hapily convert text into column names.
You can set up parameters like so (using the field names from your dataset as values):
Name: Sort1
Available Values:
Label Value
====== =======
a a
b b
c c
d d
One for each sort you may need. It sounds like 3 sort parameters will do you.
Then, in the sort section of your tablix (or table):
Column
===============================
Sort By: Parameters!Sort1.Value
Then by: Parameters!Sort2.Value
Then by: Parameters!Sort3.Value
Beware your parameter values need to be in the same case as the field names, but your labels can be anything you like.