Macro to check barcode scans

I have a barcode scanner that downloads all scans into column A, each scan being a cell in column A listed sequentially.

EXAMPLE:

END

X342

Y2342

Z2342

END

X121

Z131

Y324

END

X4343

Z1431

Y3554

END

The scans are (X,Y,Z) coordinates with an "END" scan that separates each X,Y,Z coordinate into a group. The group represents a location. Each group should have only one X, one Y, and one Z scan. I need a macro that will check to see that each group (between "END" scans) has the 3 coordinates, no more, no less. Basically checking for duplicate scans or missed scans or missed "END" scans.

I need a macro to find errors such as these:

END (Two X scans and no Z scan)

X12312

X1231

Y1132

END (no Z scan)

X12123

Y123123

END (Two Z scans)

Y12131

X123123

Z5435

Z4234

END

The macro doesnt need to fix anything just alert the user that there are X number of groups that have errors. I am at a complete loss on where to start. Any help is much appreciated. Thanks in advance.

http://www.ozgrid.com/forum/showthread.php?t=180048