Hi Frazer,
In such case
You will have 2 plans:
1st one will be a Strategy plan with unit WEEK as discussed above and the
2nd one will be a single cycle plan with 10 weeks frequency.
Start-of Cycle Dates should be matched.
Then
You need to take help of user-exit IPRM0003 , the logic written there will be skipping the 9 week trigger.
Jogeswara Rao K