I'm sorry, you're right - there's no wmf printing in PdfCreator. But, otoh, DCad does have wmf export, so you can do it directly.
The problem with Inkscape is that, though a wonderful (opensource) program, it lacks proper documentation. And (at least in v0.46) the layer management is nowhere near intuitive. Still -- I've downloaded 0.47 - and as much documentation as I could find - and will give it another go.
I believe they're working with greater Gimp compatibility, too, so that should be another plus.
btw, Thanks for reminding me about Inkscape. I've a strong hunch that it's going to be a lot more important in my workflow in the next few months.