This character is a Other Letter and is mainly used in the Cham script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. U+AA28 forms an orthographic syllable in Brahmic scripts with similar characters, which prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
The Cham script (Cham: ꨀꨇꩉ ꨌꩌ)is a Brahmic abugida used to write Cham, an Austronesian language spoken by some 245,000 Chams in Vietnam and Cambodia. It is written horizontally left to right, just like other Brahmic abugidas.
Representations
System
Representation (click value to copy)
Nº
43560
UTF-8
EA A8 A8
UTF-16
AA 28
UTF-32
00 00 AA 28
URL-Quoted
%EA%A8%A8
HTML hex reference
ꨨ
Wrong windows-1252 Mojibake
ꨨ
Encoding: GB18030 (hex bytes)
82 37 A0 33
RFC 5137
\u'AA28'
Bash and Zsh inside echo -e
\uAA28
C and C++
\uAA28
C#
\uAA28
CSS
\00AA28
Excel
=UNICHAR(43560)
Go
\uAA28
JavaScript
\uAA28
Modern JavaScript since ES6
\u{aa28}
JSON
\uAA28
Java
\uAA28
Lua
\u{AA28}
Matlab
char(43560)
Perl
"\x{AA28}"
PHP
\u{aa28}
PostgreSQL
U&'\AA28'
PowerShell
`u{AA28}
Python
\uAA28
Ruby
\u{aa28}
Rust
\u{aa28}
Click the star button next to each label to set this representation as favorite or remove it from the favorites. Favorites will be shown initially. (Favorites are stored locally on your computer and never sent over the internet.)