Hi,
This seems to be similar to daggerfall. In daggerfall it was possible to do, because it supports absolute mouse. This is problem in win95. With absolute mouse you can define start and end of mouse dragging. This is not possible if game does not support absolute mouse. What you can do is put over self two widgets, key widget on top and mouse widget below. Key widget will be “non blocking”. Mouse widget will be “click”. This way you trigger both widgets at once and you can swing with relative mouse to do attack.