Vlookup formula that adds two columns possible?

I have a vlookup formula that finds a value based on text in a column on the same worksheet the formula is in. It retrieves the value from column 2 in a list on another worksheet. Can I modify the formula to add the value it looks up with a value in column 3 on the same sheet (add columns 2 and 3 together)?

The current formula is:

=IF(ISTEXT(C23),(VLOOKUP('10-50'!C23,'Rented Equipment'!$A$1:$B$130,2,FALSE)),"")

In essence can I make it add together 'Rented Equipment'!$A$1:$B$130,2 with 'Rented Equipment'!$A$1:$B$130,3?

Thank you!