Using A Value To Adjust A Cell Reference

I have a spreadsheet set up for my son to roll up D&D characters. There's a combo box to select Race and another for Class of character. What I now need to do is automatically insert the correct set of racial and class bonuses into the relevant squares.

The Combo box points to a list of Races on Sheet 0, in cells A3 to A12. The cell reference for this returns a value between 1 and 10 depending on race selected, i.e. 'Dragonborn' yields a 1, and 'Tiefling' yields a 10. Cells H3 to H12 contain the Strength modifier for the different races.

When I select for example a Dragonborn (1) in the combo box, I want the Strength Modifier cell to pick up the value from cell H3, and if i change the selection to Tiefling (10) I want the strength modifier cell to pick up from (obviously) cell H12

How do I use a variable in the cell reference to adjust the cell data is retrieved from?