multiple criteria vlookup in vba userform

Hello all,

I have a problem with vlookup, some of the items in the lookup array are not unique and vlookup gets confused with multiple matches,

however if I can use a combination of 1st and second columns as the criterion then it would result in a unique match.

Problem is I don't know how to acheive this in vba (but I can with the worksheet formulas).

Any advice? (attached is a sample worksheet)