Jilang and SimL--- you're welcome. I'm glad I could be of some help.
The IMEPad works wonders. =) I'm not using Windows right now, but if I recall correctly, the New Phonetic input method is capable of inputting 爲.
Did you get the updated 2003 version?
http://www.microsoft.com/downloads/deta ... n#filelist
You can get an open source alternative of New Phonetic, called New Chewing (新酷音), here: http://chewing.csie.net/
It also helps to know ChangJei (爲 is bhnf = 月竹弓火). =)
As for proper tone marks: Taiwan's Ministry of Education provides a free (and very decent) TL (台羅, the Ministry of Education's official 閩南語 romanization system) input method:
http://www.edu.tw/EDU_WEB/EDU_MGT/MANDR ... loo1-1.htm
I also used to use toCyrillic, a Firefox extension.