Do you have a field that indicates when it started billing? You could do something like
var number billing = SumValues(GetRecords("{96.EX.'" & [Record ID#] & "'}",[_DBID_BILLINGS]),**Billing Field Value**)
If([Your Previous Formula]>=7,
$billing * 7,
$billing * [Previous formula with # of days billed]
Granted, I have no idea if that will work as I didn't test it first. That is what I would start with though, it seems at least to be in the right path. I hope that helps!
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Sean Connaughton
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