EXcel Del text - other than-start letters MB

Hello,

Input
Excel file with one column.

Conditions
I would like to delete text other than which is having starting letters of "MB" or "SM" and "CY".(some time more)
In other word delete text other than starting letters "MB" or "SM" and "CY".

Output
i would like delete text and rows respectively also.(other than strating letter "MB" or "SM" and "CY".)

Regrads
Anand