I do not see the option import/export using StrucLink under User Tools section.
There could be few reasons behind this.
1) You must not have installed the StrucLink while installing STAAD.Pro.
2) You may have installed StrucLink sperately, but there is a version mismatch.
To fix it, uninstall STAAD.Pro & any version of StrucLink you may have from Control Panel (Add/Remove Program or Programs and Feathures)
Reinstall STAAD.Pro, for Windows Vista/7/8 operating system, right-click on the .msi./.exe file and select the option "Run as administrator" (though you are logged in as administrator). If you run the file as the local administrator only, the program will not be installed properly. "Run as administrator" option is a must; you may need help from your IT personnel. Ensure that the check box next to the "Install companion product" is checked.
Once installation is done successfully, you should see the following options under "User Tools" section.
Note : The Export Using StrucLink and Import Using StrucLink options are now taken out from STAAD.Pro as these are not required anymore. STAAD.Pro now supports data exchange through ISM ( accessed through File > ISM ) which can be used to exchange data between STAAD.Pro and other Bentley products or third party software like Revit, Tekla Structures.