Existing NSIS Installer script updates

In need a few hours of work to be done in a existing NSIS installer. For example, insert code in the NSIS script that checks that the user is in Admin mode before proceeding with installation, if not, quit the installation. Check for what version of VC++ is installed in the target machine etc. Must have NSIS installer experience. The application already has a NSIS installer running that successfully install the application in target machine. This should not take more than three hours of work, if you are experienced.