Are you looking for a formula that will calculate the time in a
separate cell?

If so, the following formula will do:
=TIME(0, LEFT(A2,LEN(A2)-4),MID(RIGHT(A2,4),1,2))+RIGHT(A2,2)/8640000

Assumption: there will always be two digits for the seconds and
hundreths of seconds. In other words, we have the format: mm:ss.00. Use
this format in your destination cell.

HTH
Kostis Vezerides