Survey 123 Connect -- Integer Format

[JeffSilberberg]

Have a working 123 Connect Application - 

One Field is a Select one string, a second field is an Integer both are esriFieldType: NULL.  I want to combine these two for a resulting 6-character string that goes to Esri as a string.

So I added a hidden row and calculated the value of contact(${filed1}, string(${field2})).   This works great except for numeric values below 100.   Can anyone tell me how I force a mask of ### so that 5 is 005 and 50 is 050 in the resulting string and the full value will be 6-characters ABC005? 

TIA -- 

[JeffSilberberg · Accepted solution]

Found a solution -- Value + 1000 convert to string then substr(value, 1, 4)