 
					
				
		
I want to join these two types of data:
The following events have the recorded value for each step in a test.
TestNum        StepNum       recordedValue  
AFKE-232322    501           32.254 
  AFKE-232322    508           1.0223 
  AFKE-232322    842           1.0582 
  AFKE-232322    805           -24.25 
  AFKE-232322    503           22.0 
  AFKE-232322    504           100.05
The following table (lookuptable) has the instrument name used on each block of the test. (A test has multiple blocks, each block has multiple steps, and each block use an instrument.) The Instrument field has string values like "DMM_23s3".
TestNum        Block       InstrumentUsed
AFKE-232322    100         inst_1
AFKE-232322    200         inst_2
AFKE-232322    300         inst_3
AFKE-232322    400         inst_4
At the end, I would like to have something like this:
TestNum        StepNum       recordedValue  Instrument
  AFKE-232322    501           32.254         Inst_5
  AFKE-232322    508           1.0223         inst_5
  AFKE-232322    842           1.0582         inst_8
  AFKE-232322    805           -24.25         inst_8
  AFKE-232322    503           22.0           inst_5
  AFKE-232322    504           100.05         ints_5
Note that the block number is always the first step on the block and it could be any positive integer. To find the block of a step, I need to look for the two blocks before and after a step. 
Examples of blocks and their steps:
Block 502 { 503, 504, 550, ... ,634}
Block 650 { 651, 652, 653}
Block 655 { 656, 657, 658}
step 634 is part of block 502
step 652 is part of Block 650
step 657 is part of Block 655
