Thank you for that advice about the System Folder, Serval
I did indeed find another .dll file from Paint Shop users Group and it works now! Unfortunately, I put it into my System folder before I read your warning above. Mabey I'll try to fish it out.
I worked on this for 2 days and was extremely fustrated because the filter actually worked one time then quit! Thanks for your and everyone elses help.
By the way, the link for the .dll that enables 'Remove White' with PSP7 is...
Paint Shop Pro Users Group: Installing Filters
...Again, thanks for your help guys.