No, it can't. It's difficult to edit the .pto to produce a file that PTGui will accept, because PTGui uses a dummy image to hold global parameters. This has the effect of altering the numbering of the actual images and hence the image reference numbers in the control points - e.g. n0 -> n1.
One fairly easy solution which might be good enough is to create a new PTGui project and add the images files. Then copy/paste the control points from the .pto file into the .pts file. Then optimize. For this to work, you need to add an extra dummy image into the Hugin project and move it up to the top of the lens list so that the control point image numbers then start at n1 instead of n0.
John