[0] There is some fine-detail that can cause surprised outcome. Suppose the data does not contain a separator, or that the data is missing, say the last one and without the trailing separator, correct result will not be returned. I would suggest taking care of that as well.
[1] This is another rendering of the same functionality with that detail taken care of as well.
[1.1] first two named templates
[tt]
<xsl:template name="s-before">
<xsl

aram name="s" />
<xsl

aram name="sep" />
<xsl:choose>
<xsl:when test="contains($s,$sep)">
<xsl:value-of select="substring-before($s,$sep)" />
</xsl:when>
<xsl

therwise>
<xsl:value-of select="$s" />
</xsl

therwise>
</xsl:choose>
</xsl:template>
<xsl:template name="s-after">
<xsl

aram name="s" />
<xsl

aram name="sep" />
<xsl:choose>
<xsl:when test="contains($s,$sep)">
<xsl:value-of select="substring-after($s,$sep)" />
</xsl:when>
<xsl

therwise>
<!-- or some alternative default value, you've the freedom here -->
<xsl:value-of select="''" />
</xsl

therwise>
</xsl:choose>
</xsl:template>
[/tt]
[1.2] The main logic flows like this.
[tt]
<xsl:variable name="runner" select="." />
<xsl:variable name="url">
<xsl:call-template name="s-before">
<xsl:with-param name="s" select="$runner" />
<xsl:with-param name="sep" select="'|'" />
</xsl:call-template>
</xsl:variable>
<xsl:variable name="url-after">
<xsl:call-template name="s-after">
<xsl:with-param name="s" select="$data" />
<xsl:with-param name="sep" select="'|'" />
</xsl:call-template>
</xsl:variable>
<xsl:variable name="width">
<xsl:call-template name="s-before">
<xsl:with-param name="s" select="$url-after" />
<xsl:with-param name="sep" select="'|'" />
</xsl:call-template>
</xsl:variable>
<xsl:variable name="width-after">
<xsl:call-template name="s-after">
<xsl:with-param name="s" select="$url-after" />
<xsl:with-param name="sep" select="'|'" />
</xsl:call-template>
</xsl:variable>
<xsl:variable name="height">
<xsl:call-template name="s-before">
<xsl:with-param name="s" select="$width-after" />
<xsl:with-param name="sep" select="'|'" />
</xsl:call-template>
</xsl:variable>
[/tt]
[2] The difference can be seen using sample (or some variation of it containing only width but without trailing "|" etc) like this.
[tt] <xsl:variable name="runner" select="'http:host/path/110209ATDdigitaldailyFINAL_115x65.jpg'" />
[/tt]