If your selenium test is in :
src/squashTA/resources/selenium-test/src/main/java/org/squashtest/ta/selenium/PetStoreTest.java
With a such structure, the test automation script to run the selenium test (which is in the package org.squashtest.ta.selenium) is :
TEST :
LOAD selenium-test/src/test AS seleniumTestSource
CONVERT seleniumTestSource TO script.java(compile) AS seleniumTestCompiled
CONVERT seleniumTestCompiled TO script.java.selenium2(script) USING $(org.squashtest.ta.selenium.PetStoreTest) AS seleniumTest
EXECUTE execute WITH seleniumTest AS seleniumResult
ASSERT seleniumResult IS success
If your selenium test has some dependencies to other libraries (like to spring in your case), you have to add those depencencies as dependency of the squash-ta-maven-plugin in the pom.xml of your Squash TA project