Transform Duplicate rows to columns

The following code performs the following:

From:
word1 ; word_a
word1 ; word_b
word2 ; word_c
word2 ; word_d
word2 ; word_e

To:
word1 ; word_a ; word_b
word2 ; word_c ; word_d ; word_e
word3 ; word_f

Please Login or Register  to view this content.

However I want the ability to transpose two columns i.e. word_a and word_1

From:
word1 ; word_a, word_1
word1 ; word_b, word_2

To:

word1 ; word_a ; word_1;word_b;word_2

Can anyone help?