Nobody seems to know a whole lot about who Capt. J. Dubecq was, but there are a lot of graves in Avoyelles Parish cemeteries with "Dubecq" markers. According to Art Bergeron's "Guide to Louisiana Confederate Military Units," the unit was organized in 1863 in Marksville and served as a headquarters guard in the District of Western Louisiana. Dr. Bergeron's book on "Boone's Louisiana Battery" confirms that J. B. Lemoine was wounded in the foot by a shell at the Battle of Mansura. Your chronology is a little backwards, though. Lemoine would have been in Dubecq's first, then when that unit disbanded he would have joined Boone's Artillery and gone to Port Hudson, been captured, paroled and exchanged, and been wounded at Mansura a year later.