How to remove chars by index?

[YanivZi]

How i remove a fixed position characters from number?  it's always the 7th and 17th characters

Original: 00678430031017007

Remove chars in red: 00678430031017007

Result: 006784003101700

Edit:

Iv'e tried: 

left(@12,6)&mid(@12,6,4)&mid(@12,10,3)&mid(@12,13,2) AS GushHelka,

but it did not worked because it have removed the zeros.

[BrunPierre · Accepted solution]

load *,
Left(Field,6) &MID(Field,8,9) AS GushHelka;

load * Inline[
Field
00678430031017007];