I cannot figure out what it is you want to know.
It sounds like you are selecting a date from each of two combo boxes, and applying an entered value to all the months between the selected dates. Is that it?
If cDate1=the date from combo box1, and cDate2=the date from combo box2, then
Then
numMonths=DateDiff("m",cDate1,cDate2) returns the total number of months between cDate1 and cDate2.
You could then use this in a For-Next loop
For n=1 to numMonths
newdate=DateAdd("m",n,cDate1)
... do other stuff based on newdate.
Next 'n
The DateDiff and DateAdd functions are both standard VBScript functions. The "m" parameter in each specifys that you want to work with months rather than days, years, seconds or whatever else.
Hope this helps.
Tim