If the existing node types do not suite your needs, you can extend Yawet with custom nodes. They are programmed in Java and put as a jar file in the same directory, where the yawet.jar resides.
http://www.informatrix.ch/yawet/yawetExt.jar is an example of such an Extension. It contains one node, which allows you to add manual test steps. Download the source code as a ziped eclipse project http://www.informatrix.ch/yawet/yawetExt.zip. Unzip it in your workspace and follow the instructions in the readme.txt.
In case you do not have sufficient Java knowledge resources, we are always happy, if you consider to contact our sales representative to discuss your testing and our pecuniary needs :-). yawet@informatrix.ch