Copy from CHAR to CHAR

Hi, help me please.

I copy data from one internal table (1_table) in another internal table (2_table).

Copy number "7777" from the field of CHAR (10) in "1_table" in the CHAR (10) in "2_table".

In the second table I have to get the value "0000007777".

How can I do this in ABAP?