F-GRGG is shown on FlightRadar 24 to have flown the following:
HO482TW seen @ 2013-06-05 08:33 UTC
The matches the time of your flight and although the flight is HOP 3482, the 482 also matches. Many HOP flights seem to exhibit this call sign where only the last three numbers are included along with two seemingly random letters.
Looking at FlightStats, it seems this plane then flew to LIL
as HOP 3473 and returned to MPL
as HOP 3474.
libhomeradar has the following:
2013/06/05 11:41 HO473XN - F-GRGG unknown airline E145
2013/06/05 13:41 HO474SA - F-GRGG unknown airline E145
The plane then flew back to SXB
as HOP 3485. FlightRadar 24 shows F-GRGG as follows:
HO485ZI seen @ 2013-06-05 15:31 UTC
So I am confident that F-GRGG is the registration you are looking for despite the differences in call signs.