Delete duplicates from a StringList Collection

I have a Stringlist Collection that I have populated with every attribute value for all the components in the design in the format:

objAttrStringList.Append(".ATT_COM " & RefDesVal & " " & chr(34) & objAttribute.Name & chr(34) & " " & chr(34) & objAttribute.Value & chr(34))

a typical string looks like this:

.ATT_COM R334 "PKG_TYPE" "0402"

However I have duplicates in the stringlist collection.

Do anyone have any suggestions for sorting and removing duplicates.

Keep in mind that for a large design, it could potential be a lot of strings. In the one I'm working on right now there are about 25000....

Best Regards

Geir Tore