Checking if cell contains part of a string in another cell.

Thinking of it like this, I have 2 columns of data, and the Right column has a string of text, e.g Qsdf, and the left column has the string in it, usually without the Q, eg sdf.
This data goes for around 500 rows, so I am wondering if a macro would be possible that checked to see that the left hand column is contained within the right hand column, for each row, and maybe producing a MsgBox if not?

Ive tried coding it but I cannot seem to rationalise it in my head, I know you would define a string, then select the RHS column but how does one compare it the the LHS, Using loops?

Alex