Dynamically assign field value of one structure as a field name of another structure

Dear ABAPers,

I have an internal table/structure X (extract from Custom table ) with several fields. One of the field value of internal table/structure X is a field name of another internal table/structure Y ( extract of another custom table )

Now i need to pick the field of internal table X, perform some logic to get a value to that field and pass both the field name and field value to internal table Y..

Ex :

1. Internal table X derived from Custom table

Int Tab X :

Field 1 - Material

Field 2 - Qty

Field 3 - Value

Do some processing to get the value of "Field2" and pass the values to Internal table Y as shown below ( expected output)

Int Tab Y :

Material - XYZ

Qty - 100

Value - 10

Tried Field symbols but unable to find solution...

Need help on this logic please.
Thanks in advance...