• A single statement?

    SET @T = '03' πŸ˜‰

    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?

    β€œWrite the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw

    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