How do I develop a model to adjust these following drivers:

(1) size of transaction

(2) capital structure composition (use senior debt, subordinated debt, and equity)

(3) assume senior debt is floating rate and referenced to LIBOR; subordinated debt is fixed rate

(4) make an assumption for yields on each capital structure component

How do I use quarters as time periods to calculate the IRR on each capital structure component and a total blended IRR.And calculate total Enterprise Value at the time of sale to reach a 20% IRR on Equity?