No worries, have solved it. Just added an extra case to read in the
value of the first column (by looking for the "C1" at the end of the
name) as the loop cycles through, so when it gets to the column with
the "X" in it it has a value already there waiting which is overwritten
if not needed. Pretty obvious when you think about it! Probably the
result of working a 12 hour day with either too much or too little
coffee, not sure which yet.

Thanks for looking anyway,

Ross.