Adding the next number to a name to create unique number

[rgirardi]

Hi
I want to add a formula to cell A2 and then the rest of column A so that when the initials are entered into cell B2the formula in A2 take the initals and add the nect sequential number to create a unique request ID. The trick is that there can be diffrent sets of initials so I need it to give the next number for those initals not just count the cells. See below example. thanks

Request ID Auditor Initials /Requestor Initials
CE/RG1 CE/RG
ER/RG1 ER/RG
CE/RG2 CE/RG
BG/RG1 BG/RG
CE/RG3 CE/RG

[Ron Coderre]

With your list in Col_B, starting in cell B2
this regular formula begins the sequence you're asking for:
A2: =B2&COUNTIF(B$1:B2,B2)

Copy that formula down as far as you need.

Is that something you can work with?