You can configure sudo on the machine to ask for the user password, and grant root privilege only for this command and no other (better security wise).
You need to edit the file /etc/sudoers, it is done in console with the special editor visudo, just type the visudo command as root.
To force sudo to ask for the user password comment out the lines (not needed on every distro, ie. not on Ubuntu) :
#Defaults targetpw # ask for the password of the target user i.e. root
#ALL ALL=(ALL) ALL # WARNING! Only use this together with 'Defaults targetpw'!
just as they are above. Then grant permission for the sudoing user to use the command you want with :
user_login ALL = (root) PASSWD: /bin/mount -t smbfs -o username=swu //macx/swu /home/$USER/Desktop/Share
"user_login" as to be replaced by the allowed users (user1, user2, user3...), "ALL" means from any location, local or remote, "PASSWD" isn't always necessary as it is the default, "NOPASSWD:" would grant permission without asking for a password,then the command you want to allow with full path to the executable since sudo doesn't change the user's PATH variable (command1, command2...).
Hope it helps, as usual "man sudo" is a good idea for there is differences in "sudo" use between distributions.