How to get MID unspecified count data of cell

Hi,

In one cell, I am trying to create a formula to take the mid length of text (where the mid length changes but the left and right characters either side do not i.e. (14 chars)+'mid text'+(4 chars).

e.g. AR5555-dwg[1]-Public Domain Interface - Context Plan.dwg

All I have come up with is:
=RIGHT(A2,LEN(A2)-14)
Which gives me 'mid text'+(4 chars)
In a second column:
=LEFT(B2,LEN(B2)-4)

Is there a way of creating a formula combining the two in one column?

Thank you.