Without knowing any details of the tag implementations it's impossible to say for sure. Do you have the source code for the tag handlers?
Usually tag sets like this are geared towards display of data, but not processing of data (since that's the sort of thing you shouldn't be doing in a
JSP in the first place).
If the package is well-written and the authors intended such, there may be a
Java API (that the tag handlers themselves use) exported for use in
Servlets to perform just such tasks as you are asking about.
[ September 02, 2004: Message edited by: Bear Bibeault ]