A single statement?
SET @T = '03' π
Or perhaps
SET @T = REVERSE(LEFT(REVERSE(@T),2))
Or even
SET @T = substring(@T, 6, 2)
All of these (and Gail's solution) will give the result "03". Is there something more to your problem?
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden