How do I define a particular dir in front of PATH variable and then run some job and then at the end of job SET the PATH variable to original?

in a script, WILL something like this work:

ORIG_PATH=$PATH
export PATH=/dir1/dir2:$PATH

RUN SOME JOBS .....

unset PATH
EXPORT PATH=$ORIG_PATH

Also is there a way to not UNSET the path and look for particular dir and take it out from PATH variable??