Hello Don, thanks for your great reply and YES this is exactly what I'm trying to do.
However, I just can get this to work on my form. Up-until you replying, I had found a way of doing this, just playing around with rules and filters etc, I really don't know how I managed it but somehow managed to change a filter condition to become an expression?
looks something like this: . = current()/../my:field46
Like I say, I have no idea where this came from but it does count the right values the only problem now is. Some of the values that come in from the secondary repeating table, they have merged data from SharePoint and some do have double or triple values. So I'd like to somehow change this line for one that says "contains". and I think I could nail it.
Field46 by the way is the field I have setup in a repeating table and given it all the default values (hard coded) with APS, Transmission, Oil (parameters etc). Kinda doing a lookup on these values against the secondary repeating table values and doing a count yeah?
One other thing Don, I will want to submit these count results back to SharePoint - I know in the past using calculated fields, they don't promote to SP, do they?
Thanks for your help, Its much appreciated
Mike