Excel Querry - Reply Needed

Dear Sir(s),

I am having doubt, kindly clarify;

1) "A" cell having some text data, basing on that with formula automatically get the wanted result in "B" column

say for example;

A is having Hyderabad

In B  cell formula should get result like, if A is having Hyderabad, update with "ABC Limited" other wise "XYZ limited".

2) if A cell having Alpha numeric data ABCDE1253MXM007, I have to put formula from right to 4th letter is "M" or "D" result to be updated.

Kindly give suitable formula.

Thanks in Advance.