Create Triple Key to avoid SYNC

[#1]

Hey, i have this problem-

I don't know how to create a triple key  between 2 tables, that are already created AND connected by 2 fields.

Initial situation:

TABLE A:

Field A

Field B

Field C

Field D

TABLE B:

Field A

TABLE C:

Field C

Field D

I want to create a Key between Table A and Table C with those fields, C-D

Final situation:

TABLE A:

Field A

Field B

Field C

Field D

KEY

TABLE B:

Field A

TABLE C:

KEY

How can i do that? I create an autonumber on table C when its created with those 2 fields, but can't do that in Table A when its created because its a Table that has been created "after" (joining fields, concatenating, etc).

Its a way to avoid the SYNC Key, that appears with the 4 fields of Table 1-

Thanks!

[Anonymous]

Hello, I wait you serve

TABLE A:

Autonumber(Field C&'_'&Field D,'Key1') as Key1

Field A

Field B

Field C

Field D

TABLE B:

Field A

TABLE C:

Autonumber(Field C&'_'&Field D,'Key1') as Key1

Field C as TableC.FieldC

Field D as FieldD.FieldD

[#3]

Yeah, the thing ive forgot to say is that is that FIELD C is already an autonumber

And if i put LOAD C on the script, it says that its not known.. because the "real" fields are those that includes that key (suppose FIELD E and FIELD F)

So i have to put

Autonumber(FIELD E,FIELD F,FIELD D) on TABLE 1?

And this: Table1 its created after doing some operations like joins. So, i dont have that structure of "LOAD A,B,C"..

I have to "PUT" or "APPLYMAP" that KEY of Table C into Table A

Do u understand?

Thanks!