Not sure...you might want to ask on the forums @ the
XWA Upgrade Project, but you might want to download and install AlliED on your laptop (so it installs properly...just transfering files from your desktop to your laptop usually doesn't work when installing applications). Assuming the mission modifications you made on your desktop machine were saved as .tie files, those can be transfered to your laptop without problems as long as they're still in the XWA mission folder on your laptop, and they will be playable by your laptop's copy of XWA.