It is an approximation of course, but from the CV you would see two irreversible process, one reduction and one oxidation peaks or bands, and from those values I would convert from V to eV and have a correlation between the HOMO and LUMO... Of course using water as solvent of the system would make it impossible due to the hydrogen and oxygen production reactions, so I would use a organic solvent, as acetonitrile or DMF.

In three electrode system, Glassy carbon (working electrode), Pt wire as (Counter electrode) and Ag/Ag+ (reference electrode) with ferrocene as internal reference, first get the CV graph for ferrocene and then for your compound, HOMO or ground state oxidation potential will be the onset of oxidation of your compound in CV graph (add 0.63V to convert against NHE from Ferrocene, E0-0 can be conveniently taken from UV-Vis abs. onset and then Excited state oxidation potential tentatively also known as LUMO is as follows ESOP = [(GSOP (V) +4.7) - E0-0] eV. 

Good luck.

here is the answer very clear for organic dyes E0-0 eV, the intersection between Absorption and emission is 615 nm as in the article,( Convergent/Divergent Synthesis of a Linker-Varied Seriesof Dyes for Dye-Sensitized Solar Cells Based on the D35Donor) therefore the sum of absorption and emission is E0-0=717+541= 1258/615= 2.04 ev go to the paper and make sure that what I am saying is correct!!good luck and have fun with chemistry :) 

for HOMO see Hammad Cheema answer

Walid Sharmoukh Ahmed Sir in your answer 715+541 is it maximum intensity of absorption and emission?