I am trying to create an expression to derive a data column value based off two other data columns. In English

If VARA is greater than three characters long an the first character is "1" then VARB = VARC + ".A" + the last two characters of VARA

ELSE

If VARA is greater than three characters long an the first character is "2" then VARB = VARC + ".B" + the last two characters of VARA

ELSE

If VARA is greater than three characters long an the first character is "3" then VARB = VARC + ".C" + the last two characters of VARA

ELSE VARD

Here is my expression but it is only converting the VARA values that start with 1. Can anyone tell me what is wrong with the expression? I can probably do this using a SQL script but wanted to do it in a derived column container in my data flow. Any help is appreciated!

LEN(TRIM(VARA)) > 3 && LEFT(VARA,1) == "1" ? (DT_STR,11,1252)RTRIM(VARB) + ".A" + RIGHT(RTRIM(VARA),2) : LEN(TRIM(VARA)) > 3 && LEFT(VARA,1) == "2" ? (DT_STR,11,1252)RTRIM(VARB) + ".B" + RIGHT(RTRIM(VARA),2) : LEN(TRIM(VARA)) > 3 && LEFT(VARA,1) == "3" ? (DT_STR,11,1252)RTRIM(VARB) + ".C" + RIGHT(RTRIM(VARA),2) : (DT_STR,11,1252)VARD