I have 4 colums of data based on the results of 2 columns I would like
to have the value of the third & 4th column placed in the appropriat
cells.

Example of the data I am trying work with is shown below:

Specification|Grade UNS|P_Number|G_Number
SA-516 | 60 | 1 | 1
SA-516 | 70 | 1 | 2
SB-111 | C71500 | 34 | NA
SB-111 | C44400 | 32 | NA
SB-111 | C60800 | 35 | NA

I have created 2 comboboxes on a userform to select the specification
and grade and place it the applicable cells on the worksheet, but I
just can't seem to find a way to use the vlookup for 2 columns.

Any help would be appriciated.
Kind Regards
Martin