Find Next...Do what ...Continue... Repeat

[LiCal]

I am trying to prepare a Macro using Do While... to perform the below
text cleaning/preparation task:
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The document is consisted of several A-B-C-D points that I need to:

Find the first A : delete the text from the beginning to A
Find next B : format in text between A and B in bold
in one single paragraph.
Find next C : delete the text from B to C
Find next D : form the text from C to D in a paragraph

Find the next A : delete text from the last D to A.
then continue to find next B C D etc per the above routine
Finally, delete the text from the last D to the end of the Document
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Help/points on "find next ... select" is appreciated.