no subsex in Matlab?

I find that I can call mupad's subs type function (for symbolic expression substitution) from matlab command line, but there doesn't seem to be a corresponding subsex function. Is it called something else? How to call mupad's subsex from matlab command line? I can find documentation on subs in matlab's help but no documentation for subsex in Matlab help. Why?

Cheers, Bob Gray

Answer 1

[Andrew Newell]

There is a subsex in R2011a, but not in earlier releases.

Answer 2

[Felipe G. Nievinski]

see http://www.mathworks.com/support/solutions/en/data/1-EE934O/index.html?product=SM&solution=1-EE934O