Assigning variable from response data in Gatling

In my load testing script i needed to take out a value from the response and use it in the rest of the requests. Here is how i did it ,

here is the code snippet of how to acquire the value. My intended value was of format number-number
which is solved using very simple regex (\d+-\d+) and saved is as a variable commandId.

.exec(http("viewRecordSearchForm")
     .get("/mySite/searchStuff/searchForm")
     .headers(headers_1)
     .check(regex("""<input type="hidden" name="commandId" value="(\d+-\d+)" id="commandId"/>""").saveAs("commandId"))
)

Later this variable was used as request parameter,

.exec(http("queryForStuff")
    .post("/mySite/searchDataUsingCommandIdAndDates")
    .headers(headers_2)
    .param("""startDate""", """03/03/2012""")
    .param("""endDate""", """03/31/2012""")
    .param("""commandId""", """${commandId}""")
    )