Search to see if text exists in a column, if it does then count the row

I have 2 worksheets in Excel:

Plot

plot    region  jobCount    
1       MK      #VALUE! 
2       MK      #VALUE! 
3       MK      #VALUE!
4       MK      #VALUE! 
5       MK      #VALUE!
6       MK      #VALUE! 
7       MK      #VALUE!
8       MK      #VALUE!
9       MK      #VALUE!
10      MK      #VALUE! 

Waypoint

How would I search column D in the Waypoint table to count where the plot+region (i.e. MK1, MK2...) matches the postcode and where the sequence is equal to 1.

This is the formula I have so far:

=SEARCH(CONCATENATE(B:B,"",A:A),Waypoint!D:D,"0")

but it keeps returning #VALUE in the Plot table.

I want it to concatenate whatever is in plot and region, then check column D in Waypoint to see if there are any matches, if there is a match is the value in sequence = 1, if so then count it... (sorry if this pseudocode is not clear enough)

e.g. in the example above

• For plot 1, there are 2 matches so jobCount = 2
• For plot 2, there is 1 match so jobCount = 1
• For plot 4 there are 1 matches so jobCount = 1

I hope it makes sense, I've tried very hard to be clear!