Converting net figures to gross

Hi, there’s a lot of talk in forums about converting gross to net returns, but what about net to gross?

What would be the formula in excel to do this generally? For example, converting gross to net exposure for a bond could look like this:

=C10+rCpn*(1+0.5*C10)

Where the coupon is the portfolio yield.

But how would I convert a net figure into a gross (i.e. removing the impacts of the portfolio yield). What would the equation look like?

Looking forward to your thoughts!