Overlay with iftrail

I want to pass one hard-coded value with total sum from column 10-15 in trailer recordat specific position; can we do the overlay with iftril? I tried by adding overlay with ifthen condition but it’s not considering the condition which I gave after iftrail.
Input data:

H 000
A 010 Pune
B 020 Mumbai
C 030 Chennai
D 040 Delhi
T 000

Output data:

H 000
A 010 Pune
B 020 Mumbai
C 030 Chennai
D 040 Delhi
T 100 4

Note: 4 is the record count