Using VB script to send keystrokes to another program

I need a VB script that would enable me to look in a cell, say C3 and if it
contained a "00:00" (time hh:mm) entry trigger a series of sendkeys
statements that, for example would send a tab, down or tab, up etc to a cell
in another program.

I am able to use Sendkeys to activate windows in another program, send data
from to cells in that program, but am not sure how to translate data as in
the example above into Sendkeys statements and I assume this must be via a VB script?

Many thanks for any advice.