Really hoping someone can help me this is all sending me round the bend at the minute

I need a formula which can tell methe number of cells in E:E, on my seperate sheet called Bucket(R), which contain the word PCNF but do not contain the word TECO?

I tried =COUNTIF('Bucket(R)'!E:E, "*PCNF*")-COUNTIF('Bucket(R)'!E:E, "*TECO*") but this just subracts the numbers from each other and gives me an incorrect value!!

I also need a formula for the number of cells in E:E, again in Bucket(R), that contain CNF but not PCNF but only when F:F contains FDM-4-M?

I've almost finished all my work and just cant seem to get these two rigt, sorry it sounds soooooo confusing!!

Thankyou!!!!!!