Fortunately, with the help of Android Data Transfer tool, you can import your messages in .xml format from computer to your device or export text messages from device to computer as .xml or .txt files easily.Take a trail version of Android Data Transfer to transfer your SMS to computer.
Install the program on your PC first. Then, launch it and bring yourself to the primary window. Connect your Android phone to computer via a USB cable. Once Android phone is connected, the program will detect them automatically and shown up the window as below.
Note: Android Transfer is fully compatible with all popular Android phones like Samsung/HTC/Google/Motorola/Sony Ericsson.
Click "Information" icon on the navigation bar, then click on the SMS tab to enter the SMS management window. All your text messages will be list in front of the SMS management window as below. You can choose those messages you wanted and then click the "Export" button, you can select "Export to HTML", "Export to CSV" or "Export to Text" in the drop-down list, choose one and then choose the target folder and tap OK button on your computer in the pop-up. After finish the process, the sms will be saveed on your computer, click Open Folder to view the exported file if you need.
Now, download this program to have a try!