[DFDL-WG] Initiator with leading variable text

Hi All, I have the following data to parse. 0000|HEADER|value1|value2|value3 0001|CONTROLRECORD|value1|value2|value3 0001|RECORDTYPE1|value101|value101 0002|CONTROLRECORD|value10|value20|value30 0002|RECORDTYPE1|value1010|value1010 0000|TRAILER|value1|value2|value3 The header and trailer are always prefixed with '0000'. I am having trouble with the CONTROLRECORD. The *number* '0001' before '|CONTROLRECORD|' applies to following record types until the next *number*|CONTROLRECORD|. Can an initiator include a regular expression as part of it's text. If however possible, could an example be provided. I tried using setVariable based on the *number *with no success. Any ideas would be appreciated. Thanks John