Below is how to use #GETTABVAL to load the unrounded 410(a)(17) limits into an effective date array in a Data Default.  This would be necessary if you want to reference the limits in a salary transformation expression.  

Create a numeric effective date array to hold the plan year limits. Here's what the data default expression might look like:

; load all of the known 401(a)17 limits (for use in a salary transformation expression)
CCYY:= 'RegMaxComp.txt?' #GETTABVAL(1) & ; years in column 1
VALS:= 'RegMaxComp.txt?' #GETTABVAL(2) & ; limits in column 2

; create calendar year effective dates
B_DT:= 1/1/1900 #DATEPLUS ((1Y)*(CCYY-1900)) &

; round the calendar year dates to the beginning of the plan year containing each date
P_DT:= #BEGMTH (2 #FSTBUSDAY B_DT) &

12 #ARRAY (P_DT, VALS) ; create an effective date array