Show the full error message, which should include a file and line number. Then show us the lines in you code surrounding the line at which the error occurs at; making clear which is the actual line in error. If the rexpexp is a run-time regexp,
i.e. the pattern comes partially from a variable, then explain
where the variable gets its contents.
in reply to Re^4: extracting strings from text files
in thread extracting strings from text files
It may just be that you need to wrap that variable (if any) with \Q$variable\E.