You need 2 modifications:
1. use QUOTE to introduce something into another function
2. consider Jan=1, your formula generates zero, an invalid number for month


{QUOTE "1-{=MOD({DATE \@ "M"}+10,12)+1}-1" \@ "MMMM"}

note:
in the primary structure


{QUITE "d-m-y" \@ "MMMM"}
where "d-m-y" is a necessary parameter; you have to **create** a valid date. All you concern is the operation of month, therefore both day and year could be any number you like.