Task list , Mtc plan staratagy change & Key date weekly plan?

Dear

I dont think as a std SAP transactions will allow my below req.

1. I have created task list mtc stratagy as XXX. but i need to change as YYY.

2. The same mentioned above for MTc plan

3. I would like call the Mtc order on key date

Example Pump has weekly, monthly tasks.

1. Weekly schdules i need for every month 1st, 8th, 15th,22th no need 29th .

2. We can call the monthly ops thro Key date . Here if i have mentioned in stratagy as 28 days instead of 30 days it will call?

Pls any one have the soln

Thanks

Thenna