Creates a variable with the given name and value, for
further use in any other indexer.conf
or search.htm commands, or as a
search.htm template variable.
If the variable has previously been created with another
ReplaceVar or ImportEnv command,
then its value is replaced. The "value" parameter can
reference to other variables previously created by
ReplaceVar or ImportEnv commands.
Variables created using ReplaceVar are
considered to have the character set, speicified in
LocalCharset. When displaying
search template, they are converted to
BrowserCharset.