MS SQL Query conditions, multiple criteria within criteria

[Speshul]

Not sure if SQL is appropriate to post on here but thought I would give it a try.

I am trying to create a query which will filter results based on multiple criteria.

So for example,

Select 
MyData1, MyData2, MyData3

From 
MyDataBase

Where 
MyData1 = "Criteria"
AND (MyData2= NOT LIKE '%AGR%' AND MyData3 <> "AB")
AND (MyData1= NOT LIKE '%STR%' AND MyData3 <> "CD")

I want to EXCLUDE any record where BOTH %AGR% is present somewhere within MyData2, AND MyData3 is AB
I want to EXCLUDE any record where BOTH %STR% is present somewhere within MyData1, AND MyData3 is CD
However, if %STR% or %AGR% is present with a MyData3 value of "EF", it WILL list.

I can't figure out if my method of testing this is flawed or if the syntax is incorrect, could someone please verify?