Pre Populating a Value based on one condition

[Djmason2001]

Hi Forum,
Apologizes to ask but need some help from the wider community l

I have two asks ;

Aim 1 Currently i have a formula in Outcome (Column D) That looks at “Group id(Column B)” and where “Helper (Column C) = 'Master'” returns the value of the id(Column A)

Current Outcome Formula : =INDEX($A:$A,MATCH(B2&"Master",$B$1:$B$101&$C$1:$C$101,0)).

Id (Column A) is Maximum of 18 chars. If possible i would like to return the first 15 chars ( of the Id in column A). I have put expected outcome in Column E

Aim 2 Based on one conditions “Group id(Column B)” I would like to concatenate the values id(Column A) in Column F (outcome 2)

Criteria ;

The formula should always start with &cid=

After the equals sign i would need 1 of the ids(column A) relating to the groupid.

Group 21 Example ;
&cid=(Criteria GroupID21 Row2) = 001j000000hdOIWAA2
&cid=(Criteria GroupID21 Row3)= 0013a00001bv1rBAAQ

Full Url : &cid=001j000000hdOIWAA2&cid=001j000000hdQb6AAE

Group 25 Example ;
&cid=(Criteria GroupID25 Row4) = 001j000000hdOIWAA2
&cid=(Criteria GroupID25 Row5) = 001j000000hdPTjAAM

Full Url : &cid=0013a00001bv1rBAAQ&cid=001j000000hdPTjAAM

ID	Group ID	Helper	Outcome	Expected Outcome	Outcome 2
001j000000hdOIWAA2	21	Master	001j000000hdOIWAA2	001j000000hdOIW	&cid=001j000000hdOIWAA2&cid=001j000000hdQb6AAE
001j000000hdQb6AAE	21	Non Master	001j000000hdOIWAA2	001j000000hdOIW	&cid=001j000000hdOIWAA2&cid=001j000000hdQb6AAE
0013a00001bv1rBAAQ	25	Non Master	001j000000hdPTjAAM	001j000000hdPTj	&cid=0013a00001bv1rBAAQ&cid=001j000000hdPTjAAM
001j000000hdPTjAAM	25	Master	001j000000hdPTjAAM	001j000000hdPTj	&cid=0013a00001bv1rBAAQ&cid=001j000000hdPTjAAM

Looking forward to your help
Regards

 

[Djmason2001]

Just an update,
For Aim 1 : i have used the following formula to get the expected outcome

=LEFT(INDEX($A:$A,MATCH(B2&"Master",$B$1:$B$103&$C$1:$C$103,0)),15)